﻿﻿﻿ Every Day Counts

Centred Square Prime Days

Age: 10,554 days
Date of birth
Your 28th Centred Square Prime Day is on
Wednesday
when you will be
12,641 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:

Next Prime Events
Day Age
Event
Year Age
21 Aug 2022
10,559
5
28
02 Oct 2022
10,601
47
29
27 Nov 2022
10,657
103
29
20 Jan 2023
10,711
157
29
05 Jun 2024
11,213
659
30
24 Oct 2025
11,719
1,165
32
01 Jun 2026
11,939
1,385
32
12 Aug 2026
12,011
1,457
32
17 May 2027
12,289
1,735
33
15 Aug 2027
12,379
1,825
33
03 May 2028
12,641
2,087
34
06 Aug 2032
14,197
3,643
38
18 Nov 2037
16,127
5,573
44
04 Nov 2039
16,843
6,289
46
04 Jul 2043
18,181
7,627
49
09 Mar 2072
28,657
18,103
78
28 Feb 2173
65,537
54,983
179
03 Aug 2352
131,071
120,517
358
Ordinal
Day Age
Date
Age
1st
5
28 Sep 1993
0
2nd
13
06 Oct 1993
0
3rd
41
03 Nov 1993
0
4th
61
23 Nov 1993
0
5th
113
14 Jan 1994
0
6th
181
23 Mar 1994
0
7th
313
02 Aug 1994
0
8th
421
18 Nov 1994
1
9th
613
29 May 1995
1
10th
761
24 Oct 1995
2
11th
1,013
02 Jul 1996
2
12th
1,201
06 Jan 1997
3
13th
1,301
16 Apr 1997
3
14th
1,741
30 Jun 1998
4
15th
1,861
28 Oct 1998
5
16th
2,113
07 Jul 1999
5
17th
2,381
31 Mar 2000
6
18th
2,521
18 Aug 2000
6
19th
3,121
10 Apr 2002
8
20th
3,613
15 Aug 2003
9
21st
4,513
31 Jan 2006
12
22nd
5,101
11 Sep 2007
13
23rd
7,321
09 Oct 2013
20
24th
8,581
22 Mar 2017
23
25th
9,661
06 Mar 2020
26
26th
9,941
11 Dec 2020
27
27th
10,513
06 Jul 2022
28
28th
12,641
03 May 2028
34
1
29th
13,613
31 Dec 2030
37
30th
14,281
29 Oct 2032
39
31st
14,621
04 Oct 2033
40
32nd
15,313
27 Aug 2035
41
33rd
16,381
30 Jul 2038
44
34th
19,013
13 Oct 2045
52
35th
19,801
10 Dec 2047
54
36th
20,201
13 Jan 2049
55
37th
21,013
05 Apr 2051
57
38th
21,841
11 Jul 2053
59
39th
23,981
21 May 2059
65
40th
24,421
03 Aug 2060
66
41st
26,681
11 Oct 2066
73