685139924 has 24 divisors (see below), whose sum is σ = 1442400960. Its totient is φ = 278176896.

The previous prime is 685139911. The next prime is 685139947. The reversal of 685139924 is 429931586.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 643397 + ... + 644460.

It is an arithmetic number, because the mean of its divisors is an integer number (60100040).

Almost surely, 2^685139924 is an apocalyptic number.

It is an amenable number.

685139924 is an abundant number, since it is smaller than the sum of its proper divisors (757261036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685139924 is a wasteful number, since it uses less digits than its factorization.

685139924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1287887 (or 1287885 counting only the distinct ones).

The product of its digits is 466560, while the sum is 47.

The square root of 685139924 is about 26175.1776307249. The cubic root of 685139924 is about 881.5759998786.

The spelling of 685139924 in words is "six hundred eighty-five million, one hundred thirty-nine thousand, nine hundred twenty-four".