15139931 has 4 divisors (see below), whose sum is σ = 15396600. Its totient is φ = 14883264.

The previous prime is 15139921. The next prime is 15139937. The reversal of 15139931 is 13993151.

It is a happy number.

15139931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 15139931 - 2¹⁸ = 14877787 is a prime.

It is a super-2 number, since 2×15139931² = 458435021369522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15139937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128246 + ... + 128363.

It is an arithmetic number, because the mean of its divisors is an integer number (3849150).

Almost surely, 2^15139931 is an apocalyptic number.

15139931 is a deficient number, since it is larger than the sum of its proper divisors (256669).

15139931 is an equidigital number, since it uses as much as digits as its factorization.

15139931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256668.

The product of its digits is 3645, while the sum is 32.

The square root of 15139931 is about 3891.0064250782. The cubic root of 15139931 is about 247.3857228445.

The spelling of 15139931 in words is "fifteen million, one hundred thirty-nine thousand, nine hundred thirty-one".