15291631 has 2 divisors, whose sum is σ = 15291632. Its totient is φ = 15291630.

The previous prime is 15291629. The next prime is 15291641. The reversal of 15291631 is 13619251.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15291631 - 2¹ = 15291629 is a prime.

It is a super-2 number, since 2×15291631² = 467667957280322, which contains 22 as substring.

Together with 15291629, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 15291631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15291641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7645815 + 7645816.

It is an arithmetic number, because the mean of its divisors is an integer number (7645816).

Almost surely, 2^15291631 is an apocalyptic number.

15291631 is a deficient number, since it is larger than the sum of its proper divisors (1).

15291631 is an equidigital number, since it uses as much as digits as its factorization.

15291631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 28.

The square root of 15291631 is about 3910.4515084578. The cubic root of 15291631 is about 248.2092352745.

It can be divided in two parts, 1529 and 1631, that added together give a triangular number (3160 = T₇₉).

The spelling of 15291631 in words is "fifteen million, two hundred ninety-one thousand, six hundred thirty-one".