Every Day Counts
Centred Triangular Prime Days
 
Age: 25,956 days
Date of birth
Your 31st Centred Triangular Prime Day is on
Sunday
when you will be
27,541 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
26 Mar 2025
25,969
13
71
09 Dec 2025
26,227
271
71
30 May 2026
26,399
443
72
08 Mar 2027
26,681
725
73
15 Jul 2029
27,541
1,585
75
04 Aug 2032
28,657
2,701
78
20 Jul 2036
30,103
4,147
82
24 Dec 2055
37,199
11,243
101
30 Nov 2061
39,367
13,411
107
01 Nov 2073
43,721
17,765
119
17 Dec 2075
44,497
18,541
121
31 Mar 2087
48,619
22,663
133
26 Jul 2133
65,537
39,581
179
08 Sep 2228
100,279
74,323
274
28 Mar 2252
108,881
82,925
298
29 Dec 2312
131,071
105,115
358
22 Apr 7771
2,124,679
2,098,723
5817
Ordinal
Day Age
Date
Age
1st
19
09 Mar 1954
0
2nd
31
21 Mar 1954
0
3rd
109
07 Jun 1954
0
4th
199
05 Sep 1954
0
5th
409
03 Apr 1955
1
6th
571
12 Sep 1955
1
7th
631
11 Nov 1955
1
8th
829
27 May 1956
2
9th
1,489
18 Mar 1958
4
10th
1,999
10 Aug 1959
5
11th
2,341
17 Jul 1960
6
12th
2,971
08 Apr 1962
8
13th
3,529
18 Oct 1963
9
14th
4,621
14 Oct 1966
12
15th
4,789
31 Mar 1967
13
16th
7,039
28 May 1973
19
17th
7,669
17 Feb 1975
20
18th
8,779
03 Mar 1978
24
19th
9,721
30 Sep 1980
26
20th
10,459
08 Oct 1982
28
21st
10,711
17 Jun 1983
29
22nd
13,681
04 Aug 1991
37
23rd
14,851
17 Oct 1994
40
24th
16,069
16 Feb 1998
43
25th
16,381
25 Dec 1998
44
26th
17,659
25 Jun 2002
48
27th
20,011
02 Dec 2008
54
28th
20,359
15 Nov 2009
55
29th
23,251
16 Oct 2017
63
30th
25,939
24 Feb 2025
71
31st
27,541
15 Jul 2029
75
1
32nd
29,191
20 Jan 2034
79
33rd
29,611
16 Mar 2035
81
34th
31,321
20 Nov 2039
85
35th
34,429
24 May 2048
94
36th
36,739
20 Sep 2054
100
37th
40,099
02 Dec 2063
109
38th
40,591
07 Apr 2065
111
39th
42,589
26 Sep 2070
116