Every Day Counts
Centred Triangular Prime Days
 
Age: 31,314 days
Date of birth
Your 34th Centred Triangular Prime Day is on
Wednesday
when you will be
31,321 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 Oct 2025
31,319
5
85
22 Oct 2025
31,321
7
85
02 May 2026
31,513
199
86
29 Jul 2026
31,601
287
86
23 Jun 2031
33,391
2,077
91
01 Sep 2031
33,461
2,147
91
25 Nov 2041
37,199
5,885
101
02 Nov 2047
39,367
8,053
107
04 Oct 2059
43,721
12,407
119
18 Nov 2061
44,497
13,183
121
02 Mar 2073
48,619
17,305
133
28 Jun 2119
65,537
34,223
179
11 Aug 2214
100,279
68,965
274
28 Feb 2238
108,881
77,567
298
30 Nov 2298
131,071
99,757
358
24 Mar 7757
2,124,679
2,093,365
5817
Ordinal
Day Age
Date
Age
1st
19
09 Feb 1940
0
2nd
31
21 Feb 1940
0
3rd
109
09 May 1940
0
4th
199
07 Aug 1940
0
5th
409
05 Mar 1941
1
6th
571
14 Aug 1941
1
7th
631
13 Oct 1941
1
8th
829
29 Apr 1942
2
9th
1,489
18 Feb 1944
4
10th
1,999
12 Jul 1945
5
11th
2,341
19 Jun 1946
6
12th
2,971
10 Mar 1948
8
13th
3,529
19 Sep 1949
9
14th
4,621
15 Sep 1952
12
15th
4,789
02 Mar 1953
13
16th
7,039
30 Apr 1959
19
17th
7,669
19 Jan 1961
20
18th
8,779
03 Feb 1964
24
19th
9,721
02 Sep 1966
26
20th
10,459
09 Sep 1968
28
21st
10,711
19 May 1969
29
22nd
13,681
06 Jul 1977
37
23rd
14,851
18 Sep 1980
40
24th
16,069
19 Jan 1984
43
25th
16,381
26 Nov 1984
44
26th
17,659
27 May 1988
48
27th
20,011
04 Nov 1994
54
28th
20,359
18 Oct 1995
55
29th
23,251
18 Sep 2003
63
30th
25,939
27 Jan 2011
71
31st
27,541
17 Jun 2015
75
32nd
29,191
23 Dec 2019
79
33rd
29,611
15 Feb 2021
81
34th
31,321
22 Oct 2025
85
1
35th
34,429
26 Apr 2034
94
36th
36,739
22 Aug 2040
100
37th
40,099
03 Nov 2049
109
38th
40,591
10 Mar 2051
111
39th
42,589
28 Aug 2056
116