Every Day Counts
Centred Square Prime Days
 
Age: 14,284 days
Date of birth
Your 31st Centred Square Prime Day is on
Tuesday
when you will be
14,621 days old

A centred square prime is a centred square number that is prime.

Unlike regular square numbers, which are never prime, quite a few of the centred square numbers are prime.

Centred square numbers are of the form n2 + (n - 1)2

In elementary number theory, a centred square number is a centred figurate number that gives the number of dots in a square with a dot in the centre and all other dots surrounding the centre dot in successive square layers. That is, each centred square number equals the number of dots within a given city block distance of the centre dot on a regular square lattice. While centred square numbers, like figurate numbers in general, have few if any direct practical applications, they are sometimes studied in recreational mathematics for their elegant geometric and arithmetic properties.

The figures for the first four centred square numbers are shown below:

Remind me, please


Next Prime Events
Day Age
Event
Days Ahead
Year Age
13 Dec 2023
14,293
9
39
30 Jan 2024
14,341
57
39
26 Jul 2024
14,519
235
39
05 Nov 2024
14,621
337
40
23 Jun 2025
14,851
567
40
20 Dec 2028
16,127
1,843
44
28 May 2030
16,651
2,367
45
06 Dec 2030
16,843
2,559
46
20 Sep 2032
17,497
3,213
47
05 Aug 2034
18,181
3,897
49
27 Nov 2037
19,391
5,107
53
27 May 2039
19,937
5,653
54
11 Apr 2063
28,657
14,373
78
09 Jul 2104
43,721
29,437
119
06 Dec 2117
48,619
34,335
133
01 Apr 2164
65,537
51,253
179
16 May 2259
100,279
85,995
274
05 Sep 2343
131,071
116,787
358
Ordinal
Day Age
Date
Age
1st
5
30 Oct 1984
0
2nd
13
07 Nov 1984
0
3rd
41
05 Dec 1984
0
4th
61
25 Dec 1984
0
5th
113
15 Feb 1985
0
6th
181
24 Apr 1985
0
7th
313
03 Sep 1985
0
8th
421
20 Dec 1985
1
9th
613
30 Jun 1986
1
10th
761
25 Nov 1986
2
11th
1,013
04 Aug 1987
2
12th
1,201
08 Feb 1988
3
13th
1,301
18 May 1988
3
14th
1,741
01 Aug 1989
4
15th
1,861
29 Nov 1989
5
16th
2,113
08 Aug 1990
5
17th
2,381
03 May 1991
6
18th
2,521
20 Sep 1991
6
19th
3,121
12 May 1993
8
20th
3,613
16 Sep 1994
9
21st
4,513
04 Mar 1997
12
22nd
5,101
13 Oct 1998
13
23rd
7,321
10 Nov 2004
20
24th
8,581
23 Apr 2008
23
25th
9,661
08 Apr 2011
26
26th
9,941
13 Jan 2012
27
27th
10,513
07 Aug 2013
28
28th
12,641
05 Jun 2019
34
29th
13,613
01 Feb 2022
37
30th
14,281
01 Dec 2023
39
31st
14,621
05 Nov 2024
40
1
32nd
15,313
28 Sep 2026
41
33rd
16,381
31 Aug 2029
44
34th
19,013
14 Nov 2036
52
35th
19,801
11 Jan 2039
54
36th
20,201
15 Feb 2040
55
37th
21,013
07 May 2042
57
38th
21,841
12 Aug 2044
59
39th
23,981
22 Jun 2050
65
40th
24,421
05 Sep 2051
66
41st
26,681
12 Nov 2057
73