Every Day Counts
Centred Triangular Prime Days
 
Age: 20,018 days
Date of birth
Your 28th Centred Triangular Prime Day is on
Wednesday
when you will be
20,359 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
12 May 2025
20,021
3
54
08 Nov 2025
20,201
183
55
13 Apr 2026
20,357
339
55
15 Apr 2026
20,359
341
55
17 Dec 2029
21,701
1,683
59
02 Jan 2032
22,447
2,429
61
02 Jan 2049
28,657
8,639
78
18 Dec 2052
30,103
10,085
82
23 May 2072
37,199
17,181
101
30 Apr 2078
39,367
19,349
107
01 Apr 2090
43,721
23,703
119
30 Aug 2103
48,619
28,601
133
24 Dec 2149
65,537
45,519
179
06 Feb 2245
100,279
80,261
274
26 Aug 2268
108,881
88,863
298
29 May 2329
131,071
111,053
358
20 Sep 7787
2,124,679
2,104,661
5817
Ordinal
Day Age
Date
Age
1st
19
07 Aug 1970
0
2nd
31
19 Aug 1970
0
3rd
109
05 Nov 1970
0
4th
199
03 Feb 1971
0
5th
409
01 Sep 1971
1
6th
571
10 Feb 1972
1
7th
631
10 Apr 1972
1
8th
829
25 Oct 1972
2
9th
1,489
16 Aug 1974
4
10th
1,999
08 Jan 1976
5
11th
2,341
15 Dec 1976
6
12th
2,971
06 Sep 1978
8
13th
3,529
17 Mar 1980
9
14th
4,621
14 Mar 1983
12
15th
4,789
29 Aug 1983
13
16th
7,039
26 Oct 1989
19
17th
7,669
18 Jul 1991
20
18th
8,779
01 Aug 1994
24
19th
9,721
28 Feb 1997
26
20th
10,459
08 Mar 1999
28
21st
10,711
15 Nov 1999
29
22nd
13,681
02 Jan 2008
37
23rd
14,851
17 Mar 2011
40
24th
16,069
17 Jul 2014
43
25th
16,381
25 May 2015
44
26th
17,659
23 Nov 2018
48
27th
20,011
02 May 2025
54
28th
20,359
15 Apr 2026
55
1
29th
23,251
16 Mar 2034
63
30th
25,939
25 Jul 2041
71
31st
27,541
13 Dec 2045
75
32nd
29,191
20 Jun 2050
79
33rd
29,611
14 Aug 2051
81
34th
31,321
19 Apr 2056
85
35th
34,429
22 Oct 2064
94
36th
36,739
18 Feb 2071
100
37th
40,099
01 May 2080
109
38th
40,591
05 Sep 2081
111
39th
42,589
24 Feb 2087
116