686431944 has 48 divisors (see below), whose sum is σ = 2028096720. Its totient is φ = 208009440.

The previous prime is 686431939. The next prime is 686431961. The reversal of 686431944 is 449134686.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 686431944.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 432562 + ... + 434145.

It is an arithmetic number, because the mean of its divisors is an integer number (42252015).

Almost surely, 2^686431944 is an apocalyptic number.

It is an amenable number.

686431944 is an abundant number, since it is smaller than the sum of its proper divisors (1341664776).

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

686431944 is a wasteful number, since it uses less digits than its factorization.

686431944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866730 (or 866723 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The square root of 686431944 is about 26199.8462590909. The cubic root of 686431944 is about 882.1298033465.

The spelling of 686431944 in words is "six hundred eighty-six million, four hundred thirty-one thousand, nine hundred forty-four".