Every Day Counts
Centred Triangular Prime Days
 
Age: 23,233 days
Date of birth
Your 29th Centred Triangular Prime Day is on
Saturday
when you will be
23,251 days old

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

Centred triangular numbers are of the form (3n2 + 3n + 2) / 2

A centred triangular number is a centred figurate number that represents a triangle with a dot in the centre and all other dots surrounding the centre in successive triangular layers.

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

Remind me, please


Next Prime Events
Day Age
Event
Days Ahead
Year Age
28 Feb 2026
23,251
18
63
28 Feb 2026
23,251
18
63
09 May 2026
23,321
88
63
01 Nov 2026
23,497
264
64
28 Feb 2028
23,981
748
65
17 Dec 2040
28,657
5,424
78
02 Dec 2044
30,103
6,870
82
07 May 2064
37,199
13,966
101
14 Apr 2070
39,367
16,134
107
16 Mar 2082
43,721
20,488
119
30 Apr 2084
44,497
21,264
121
13 Aug 2095
48,619
25,386
133
08 Dec 2141
65,537
42,304
179
21 Jan 2237
100,279
77,046
274
10 Aug 2260
108,881
85,648
298
13 May 2321
131,071
107,838
358
04 Sep 7779
2,124,679
2,101,446
5817
Ordinal
Day Age
Date
Age
1st
19
22 Jul 1962
0
2nd
31
03 Aug 1962
0
3rd
109
20 Oct 1962
0
4th
199
18 Jan 1963
0
5th
409
16 Aug 1963
1
6th
571
25 Jan 1964
1
7th
631
25 Mar 1964
1
8th
829
09 Oct 1964
2
9th
1,489
31 Jul 1966
4
10th
1,999
23 Dec 1967
5
11th
2,341
29 Nov 1968
6
12th
2,971
21 Aug 1970
8
13th
3,529
01 Mar 1972
9
14th
4,621
26 Feb 1975
12
15th
4,789
13 Aug 1975
13
16th
7,039
10 Oct 1981
19
17th
7,669
02 Jul 1983
20
18th
8,779
16 Jul 1986
24
19th
9,721
12 Feb 1989
26
20th
10,459
20 Feb 1991
28
21st
10,711
30 Oct 1991
29
22nd
13,681
17 Dec 1999
37
23rd
14,851
01 Mar 2003
40
24th
16,069
01 Jul 2006
43
25th
16,381
09 May 2007
44
26th
17,659
07 Nov 2010
48
27th
20,011
16 Apr 2017
54
28th
20,359
30 Mar 2018
55
29th
23,251
28 Feb 2026
63
1
30th
25,939
09 Jul 2033
71
31st
27,541
27 Nov 2037
75
32nd
29,191
04 Jun 2042
79
33rd
29,611
29 Jul 2043
81
34th
31,321
03 Apr 2048
85
35th
34,429
06 Oct 2056
94
36th
36,739
02 Feb 2063
100
37th
40,099
15 Apr 2072
109
38th
40,591
20 Aug 2073
111
39th
42,589
08 Feb 2079
116