Every Day Counts
Centred Triangular Prime Days
 
Age: 17,629 days
Date of birth
Your 26th Centred Triangular Prime Day is on
Tuesday
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
29 Jun 2025
17,657
28
48
01 Jul 2025
17,659
30
48
09 May 2026
17,971
342
49
05 Dec 2026
18,181
552
49
16 Apr 2027
18,313
684
50
14 Aug 2027
18,433
804
50
16 Mar 2029
19,013
1,384
52
29 Mar 2030
19,391
1,762
53
18 May 2030
19,441
1,812
53
26 Sep 2031
19,937
2,308
54
11 Aug 2055
28,657
11,028
78
07 Nov 2096
43,721
26,092
119
07 Apr 2110
48,619
30,990
133
01 Aug 2156
65,537
47,908
179
15 Sep 2251
100,279
82,650
274
05 Jan 2336
131,071
113,442
358
28 Apr 7794
2,124,679
2,107,050
5817
Ordinal
Day Age
Date
Age
1st
19
15 Mar 1977
0
2nd
31
27 Mar 1977
0
3rd
109
13 Jun 1977
0
4th
199
11 Sep 1977
0
5th
409
09 Apr 1978
1
6th
571
18 Sep 1978
1
7th
631
17 Nov 1978
1
8th
829
03 Jun 1979
2
9th
1,489
24 Mar 1981
4
10th
1,999
16 Aug 1982
5
11th
2,341
24 Jul 1983
6
12th
2,971
14 Apr 1985
8
13th
3,529
24 Oct 1986
9
14th
4,621
20 Oct 1989
12
15th
4,789
06 Apr 1990
13
16th
7,039
03 Jun 1996
19
17th
7,669
23 Feb 1998
20
18th
8,779
09 Mar 2001
24
19th
9,721
07 Oct 2003
26
20th
10,459
14 Oct 2005
28
21st
10,711
23 Jun 2006
29
22nd
13,681
10 Aug 2014
37
23rd
14,851
23 Oct 2017
40
24th
16,069
22 Feb 2021
43
25th
16,381
31 Dec 2021
44
26th
17,659
01 Jul 2025
48
1
27th
20,011
09 Dec 2031
54
28th
20,359
21 Nov 2032
55
29th
23,251
22 Oct 2040
63
30th
25,939
02 Mar 2048
71
31st
27,541
21 Jul 2052
75
32nd
29,191
26 Jan 2057
79
33rd
29,611
22 Mar 2058
81
34th
31,321
26 Nov 2062
85
35th
34,429
31 May 2071
94
36th
36,739
26 Sep 2077
100
37th
40,099
08 Dec 2086
109
38th
40,591
13 Apr 2088
111
39th
42,589
02 Oct 2093
116