685594931 has 4 divisors (see below), whose sum is σ = 783537072. Its totient is φ = 587652792.

The previous prime is 685594873. The next prime is 685594937. The reversal of 685594931 is 139495586.

It is a happy number.

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 685594931 - 2¹⁸ = 685332787 is a prime.

It is a super-2 number, since 2×685594931² = 940080818825789522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 685594931.

It is not an unprimeable number, because it can be changed into a prime (685594937) 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, 48971060 + ... + 48971073.

It is an arithmetic number, because the mean of its divisors is an integer number (195884268).

Almost surely, 2^685594931 is an apocalyptic number.

685594931 is a deficient number, since it is larger than the sum of its proper divisors (97942141).

685594931 is an equidigital number, since it uses as much as digits as its factorization.

685594931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97942140.

The product of its digits is 1166400, while the sum is 50.

The square root of 685594931 is about 26183.8677624220. The cubic root of 685594931 is about 881.7711106257.

The spelling of 685594931 in words is "six hundred eighty-five million, five hundred ninety-four thousand, nine hundred thirty-one".