Every Day Counts
Centred Square Prime Days
 
Age: 23,981 days
Date of birth

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:

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Next Prime Events
Day Age
Event
Days Ahead
Year Age
11 Jul 2025
23,981
today
65
11 Jul 2025
23,981
today
65
07 May 2026
24,281
300
66
21 Feb 2027
24,571
590
67
20 Nov 2030
25,939
1,958
71
30 Apr 2038
28,657
4,676
78
15 Apr 2042
30,103
6,122
82
18 Sep 2061
37,199
13,218
101
26 Aug 2067
39,367
15,386
107
28 Jul 2079
43,721
19,740
119
11 Sep 2081
44,497
20,516
121
24 Dec 2092
48,619
24,638
133
21 Apr 2139
65,537
41,556
179
04 Jun 2234
100,279
76,298
274
22 Dec 2257
108,881
84,900
298
24 Sep 2318
131,071
107,090
358
15 Jan 7777
2,124,679
2,100,698
5817
Ordinal
Day Age
Date
Age
1st
5
19 Nov 1959
0
2nd
13
27 Nov 1959
0
3rd
41
25 Dec 1959
0
4th
61
14 Jan 1960
0
5th
113
06 Mar 1960
0
6th
181
13 May 1960
0
7th
313
22 Sep 1960
0
8th
421
08 Jan 1961
1
9th
613
19 Jul 1961
1
10th
761
14 Dec 1961
2
11th
1,013
23 Aug 1962
2
12th
1,201
27 Feb 1963
3
13th
1,301
07 Jun 1963
3
14th
1,741
20 Aug 1964
4
15th
1,861
18 Dec 1964
5
16th
2,113
27 Aug 1965
5
17th
2,381
22 May 1966
6
18th
2,521
09 Oct 1966
6
19th
3,121
31 May 1968
8
20th
3,613
05 Oct 1969
9
21st
4,513
23 Mar 1972
12
22nd
5,101
01 Nov 1973
13
23rd
7,321
30 Nov 1979
20
24th
8,581
13 May 1983
23
25th
9,661
27 Apr 1986
26
26th
9,941
01 Feb 1987
27
27th
10,513
26 Aug 1988
28
28th
12,641
24 Jun 1994
34
29th
13,613
20 Feb 1997
37
30th
14,281
20 Dec 1998
39
31st
14,621
25 Nov 1999
40
32nd
15,313
17 Oct 2001
41
33rd
16,381
19 Sep 2004
44
34th
19,013
04 Dec 2011
52
35th
19,801
30 Jan 2014
54
36th
20,201
06 Mar 2015
55
37th
21,013
26 May 2017
57
38th
21,841
01 Sep 2019
59
39th
23,981
11 Jul 2025
65
1
40th
24,421
24 Sep 2026
66
41st
26,681
01 Dec 2032
73