Every Day Counts
Centred Triangular Prime Days
 
Age: 16,373 days
Date of birth
Your 25th Centred Triangular Prime Day is on
Sunday
when you will be
16,381 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
14 Jun 2026
16,381
8
44
14 Jun 2026
16,381
8
44
14 Jun 2026
16,381
8
44
14 Jun 2026
16,381
8
44
11 Dec 2026
16,561
188
45
11 Mar 2027
16,651
278
45
19 Sep 2027
16,843
470
46
04 Jul 2029
17,497
1,124
47
19 May 2031
18,181
1,808
49
10 Sep 2034
19,391
3,018
53
09 Mar 2036
19,937
3,564
54
23 Jan 2060
28,657
12,284
78
22 Apr 2101
43,721
27,348
119
19 Sep 2114
48,619
32,246
133
13 Jan 2161
65,537
49,164
179
27 Feb 2256
100,279
83,906
274
18 Jun 2340
131,071
114,698
358
Ordinal
Day Age
Date
Age
1st
19
27 Aug 1981
0
2nd
31
08 Sep 1981
0
3rd
109
25 Nov 1981
0
4th
199
23 Feb 1982
0
5th
409
21 Sep 1982
1
6th
571
02 Mar 1983
1
7th
631
01 May 1983
1
8th
829
15 Nov 1983
2
9th
1,489
05 Sep 1985
4
10th
1,999
28 Jan 1987
5
11th
2,341
05 Jan 1988
6
12th
2,971
26 Sep 1989
8
13th
3,529
07 Apr 1991
9
14th
4,621
03 Apr 1994
12
15th
4,789
18 Sep 1994
13
16th
7,039
15 Nov 2000
19
17th
7,669
07 Aug 2002
20
18th
8,779
21 Aug 2005
24
19th
9,721
20 Mar 2008
26
20th
10,459
28 Mar 2010
28
21st
10,711
05 Dec 2010
29
22nd
13,681
22 Jan 2019
37
23rd
14,851
06 Apr 2022
40
24th
16,069
06 Aug 2025
43
25th
16,381
14 Jun 2026
44
1
26th
17,659
13 Dec 2029
48
27th
20,011
22 May 2036
54
28th
20,359
05 May 2037
55
29th
23,251
05 Apr 2045
63
30th
25,939
14 Aug 2052
71
31st
27,541
02 Jan 2057
75
32nd
29,191
10 Jul 2061
79
33rd
29,611
03 Sep 2062
81
34th
31,321
10 May 2067
85
35th
34,429
12 Nov 2075
94
36th
36,739
10 Mar 2082
100
37th
40,099
22 May 2091
109
38th
40,591
25 Sep 2092
111
39th
42,589
16 Mar 2098
116