ARSE

Sun 23 Sep 2018

Circular Prime Days

Your 34th Circular Prime Day is on

Friday

01 August 2025

when you will be

11,939 days old

A circular prime is a prime number with the property that the number generated at each intermediate step when cyclically permuting its (base 10) digits will be prime.
For example 1193 is a circular prime, since 1931, 9311 and 3119 all are also prime.
A circular prime with at least two digits can only consist of combinations of the digits 1, 3, 7 or 9, because having 0, 2, 4, 6 or 8 as the last digit makes the number divisible by 2, and having 0 or 5 as the last digit makes it divisible by 5.
The complete listing of the smallest representative prime from all known cycles of circular primes (The single-digit primes and repunits are the only members of their respective cycles) is
2, 3, 5, 7, 11, 13, 17, 37, 79, 113, 197, 199, 337, 1193, 3779, 11939, 19937, 193939, 199933, R_{19}, R_{23}, R_{317} and R_{1031},
where R_{n} is a repunit prime with n digits.

There are no other circular primes up to 10^{23}.

Next Prime Events

Day Age

Event

Days Ahead

Year Age

Ordinal

Day Age

Date

Age

1st

2

0

2nd

3

0

3rd

5

0

4th

7

0

5th

11

0

6th

13

0

7th

17

0

8th

31

0

9th

37

0

10th

71

0

11th

73

0

12th

79

0

13th

97

0

14th

113

0

15th

131

0

16th

197

0

17th

199

0

18th

311

0

19th

337

0

20th

373

1

21st

719

1

22nd

733

2

23rd

919

2

24th

971

2

25th

991

2

26th

1,193

3

27th

1,931

5

28th

3,119

8

29th

3,779

10

30th

7,793

21

31st

7,937

21

32nd

9,311

25

33rd

9,377

25

34th

11,939

32

1

35th

19,391

53

36th

19,937

54

37th

37,199

101

38th

39,119

107

39th

71,993

197

40th

91,193

249

41st

93,719

256

42nd

93,911

257

43rd

99,371

272