15131231 has 2 divisors, whose sum is σ = 15131232. Its totient is φ = 15131230.

The previous prime is 15131209. The next prime is 15131273. The reversal of 15131231 is 13213151.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15131231 - 2⁶ = 15131167 is a prime.

It is a super-2 number, since 2×15131231² = 457908303150722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15131531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7565615 + 7565616.

It is an arithmetic number, because the mean of its divisors is an integer number (7565616).

Almost surely, 2^15131231 is an apocalyptic number.

15131231 is a deficient number, since it is larger than the sum of its proper divisors (1).

15131231 is an equidigital number, since it uses as much as digits as its factorization.

15131231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90, while the sum is 17.

The square root of 15131231 is about 3889.8883017382. Note that the first 3 decimals coincide. The cubic root of 15131231 is about 247.3383279086.

Adding to 15131231 its reverse (13213151), we get a palindrome (28344382).

It can be divided in two parts, 1513 and 1231, that added together give a cube (2744 = 14³).

The spelling of 15131231 in words is "fifteen million, one hundred thirty-one thousand, two hundred thirty-one".