231515013 has 4 divisors (see below), whose sum is σ = 308686688. Its totient is φ = 154343340.

The previous prime is 231515003. The next prime is 231515021. The reversal of 231515013 is 310515132.

231515013 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 231515013 - 2¹⁴ = 231498629 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231515003) 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, 38585833 + ... + 38585838.

It is an arithmetic number, because the mean of its divisors is an integer number (77171672).

Almost surely, 2^231515013 is an apocalyptic number.

It is an amenable number.

231515013 is a deficient number, since it is larger than the sum of its proper divisors (77171675).

231515013 is an equidigital number, since it uses as much as digits as its factorization.

231515013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77171674.

The product of its (nonzero) digits is 450, while the sum is 21.

The square root of 231515013 is about 15215.6174044959. The cubic root of 231515013 is about 614.0348958229.

The spelling of 231515013 in words is "two hundred thirty-one million, five hundred fifteen thousand, thirteen".