Every Day Counts
Centred Triangular Prime Days
 
Age: 17,607 days
Date of birth
Your 26th Centred Triangular Prime Day is on
Monday
when you will be
17,659 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
20 Apr 2025
17,609
2
48
09 Jun 2025
17,659
52
48
17 Apr 2026
17,971
364
49
13 Nov 2026
18,181
574
49
25 Mar 2027
18,313
706
50
23 Jul 2027
18,433
826
50
22 Feb 2029
19,013
1,406
52
07 Mar 2030
19,391
1,784
53
26 Apr 2030
19,441
1,834
53
04 Sep 2031
19,937
2,330
54
20 Jul 2055
28,657
11,050
78
16 Oct 2096
43,721
26,114
119
16 Mar 2110
48,619
31,012
133
10 Jul 2156
65,537
47,930
179
24 Aug 2251
100,279
82,672
274
14 Dec 2335
131,071
113,464
358
06 Apr 7794
2,124,679
2,107,072
5817
Ordinal
Day Age
Date
Age
1st
19
21 Feb 1977
0
2nd
31
05 Mar 1977
0
3rd
109
22 May 1977
0
4th
199
20 Aug 1977
0
5th
409
18 Mar 1978
1
6th
571
27 Aug 1978
1
7th
631
26 Oct 1978
1
8th
829
12 May 1979
2
9th
1,489
02 Mar 1981
4
10th
1,999
25 Jul 1982
5
11th
2,341
02 Jul 1983
6
12th
2,971
23 Mar 1985
8
13th
3,529
02 Oct 1986
9
14th
4,621
28 Sep 1989
12
15th
4,789
15 Mar 1990
13
16th
7,039
12 May 1996
19
17th
7,669
01 Feb 1998
20
18th
8,779
15 Feb 2001
24
19th
9,721
15 Sep 2003
26
20th
10,459
22 Sep 2005
28
21st
10,711
01 Jun 2006
29
22nd
13,681
19 Jul 2014
37
23rd
14,851
01 Oct 2017
40
24th
16,069
31 Jan 2021
43
25th
16,381
09 Dec 2021
44
26th
17,659
09 Jun 2025
48
1
27th
20,011
17 Nov 2031
54
28th
20,359
30 Oct 2032
55
29th
23,251
30 Sep 2040
63
30th
25,939
09 Feb 2048
71
31st
27,541
29 Jun 2052
75
32nd
29,191
04 Jan 2057
79
33rd
29,611
28 Feb 2058
81
34th
31,321
04 Nov 2062
85
35th
34,429
09 May 2071
94
36th
36,739
04 Sep 2077
100
37th
40,099
16 Nov 2086
109
38th
40,591
22 Mar 2088
111
39th
42,589
10 Sep 2093
116