685661320 has 16 divisors (see below), whose sum is σ = 1542738060. Its totient is φ = 274264512.

The previous prime is 685661311. The next prime is 685661377. The reversal of 685661320 is 23166586.

685661320 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 654234084 + 31427236 = 25578^2 + 5606^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 685661320.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8570727 + ... + 8570806.

Almost surely, 2^685661320 is an apocalyptic number.

It is an amenable number.

685661320 is an abundant number, since it is smaller than the sum of its proper divisors (857076740).

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

685661320 is a wasteful number, since it uses less digits than its factorization.

685661320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17141544 (or 17141540 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 685661320 is about 26185.1354779768. The cubic root of 685661320 is about 881.7995715580.

The spelling of 685661320 in words is "six hundred eighty-five million, six hundred sixty-one thousand, three hundred twenty".