Every Day Counts
Centred Triangular Prime Days
 
Age: 31,301 days
Date of birth
Your 34th Centred Triangular Prime Day is on
Tuesday
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
31 Mar 2026
31,307
6
85
14 Apr 2026
31,321
20
85
23 Oct 2026
31,513
212
86
19 Jan 2027
31,601
300
86
14 Dec 2031
33,391
2,090
91
22 Feb 2032
33,461
2,160
91
18 May 2042
37,199
5,898
101
24 Apr 2048
39,367
8,066
107
26 Mar 2060
43,721
12,420
119
11 May 2062
44,497
13,196
121
23 Aug 2073
48,619
17,318
133
19 Dec 2119
65,537
34,236
179
01 Feb 2215
100,279
68,978
274
21 Aug 2238
108,881
77,580
298
23 May 2299
131,071
99,770
358
14 Sep 7757
2,124,679
2,093,378
5817
Ordinal
Day Age
Date
Age
1st
19
01 Aug 1940
0
2nd
31
13 Aug 1940
0
3rd
109
30 Oct 1940
0
4th
199
28 Jan 1941
0
5th
409
26 Aug 1941
1
6th
571
04 Feb 1942
1
7th
631
05 Apr 1942
1
8th
829
20 Oct 1942
2
9th
1,489
10 Aug 1944
4
10th
1,999
02 Jan 1946
5
11th
2,341
10 Dec 1946
6
12th
2,971
31 Aug 1948
8
13th
3,529
12 Mar 1950
9
14th
4,621
08 Mar 1953
12
15th
4,789
23 Aug 1953
13
16th
7,039
21 Oct 1959
19
17th
7,669
12 Jul 1961
20
18th
8,779
26 Jul 1964
24
19th
9,721
23 Feb 1967
26
20th
10,459
02 Mar 1969
28
21st
10,711
09 Nov 1969
29
22nd
13,681
27 Dec 1977
37
23rd
14,851
11 Mar 1981
40
24th
16,069
11 Jul 1984
43
25th
16,381
19 May 1985
44
26th
17,659
17 Nov 1988
48
27th
20,011
27 Apr 1995
54
28th
20,359
09 Apr 1996
55
29th
23,251
10 Mar 2004
63
30th
25,939
20 Jul 2011
71
31st
27,541
08 Dec 2015
75
32nd
29,191
14 Jun 2020
79
33rd
29,611
08 Aug 2021
81
34th
31,321
14 Apr 2026
85
1
35th
34,429
17 Oct 2034
94
36th
36,739
12 Feb 2041
100
37th
40,099
26 Apr 2050
109
38th
40,591
31 Aug 2051
111
39th
42,589
18 Feb 2057
116