Every Day Counts
Centred Triangular Prime Days
 
Age: 27,525 days
Date of birth
Your 31st Centred Triangular Prime Day is on
Friday
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
28 Nov 2025
27,527
2
75
12 Dec 2025
27,541
16
75
27 Jul 2028
28,499
974
78
01 Jan 2029
28,657
1,132
78
17 Dec 2032
30,103
2,578
82
18 Dec 2041
33,391
5,866
91
22 May 2052
37,199
9,674
101
29 Apr 2058
39,367
11,842
107
31 Mar 2070
43,721
16,196
119
15 May 2072
44,497
16,972
121
28 Aug 2083
48,619
21,094
133
23 Dec 2129
65,537
38,012
179
05 Feb 2225
100,279
72,754
274
25 Aug 2248
108,881
81,356
298
28 May 2309
131,071
103,546
358
19 Sep 7767
2,124,679
2,097,154
5817
Ordinal
Day Age
Date
Age
1st
19
06 Aug 1950
0
2nd
31
18 Aug 1950
0
3rd
109
04 Nov 1950
0
4th
199
02 Feb 1951
0
5th
409
31 Aug 1951
1
6th
571
09 Feb 1952
1
7th
631
09 Apr 1952
1
8th
829
24 Oct 1952
2
9th
1,489
15 Aug 1954
4
10th
1,999
07 Jan 1956
5
11th
2,341
14 Dec 1956
6
12th
2,971
05 Sep 1958
8
13th
3,529
16 Mar 1960
9
14th
4,621
13 Mar 1963
12
15th
4,789
28 Aug 1963
13
16th
7,039
25 Oct 1969
19
17th
7,669
17 Jul 1971
20
18th
8,779
31 Jul 1974
24
19th
9,721
27 Feb 1977
26
20th
10,459
07 Mar 1979
28
21st
10,711
14 Nov 1979
29
22nd
13,681
01 Jan 1988
37
23rd
14,851
16 Mar 1991
40
24th
16,069
16 Jul 1994
43
25th
16,381
24 May 1995
44
26th
17,659
22 Nov 1998
48
27th
20,011
01 May 2005
54
28th
20,359
14 Apr 2006
55
29th
23,251
15 Mar 2014
63
30th
25,939
24 Jul 2021
71
31st
27,541
12 Dec 2025
75
1
32nd
29,191
19 Jun 2030
79
33rd
29,611
13 Aug 2031
81
34th
31,321
18 Apr 2036
85
35th
34,429
21 Oct 2044
94
36th
36,739
17 Feb 2051
100
37th
40,099
30 Apr 2060
109
38th
40,591
04 Sep 2061
111
39th
42,589
23 Feb 2067
116