685977928 has 16 divisors (see below), whose sum is σ = 1320971580. Its totient is φ = 333718848.

The previous prime is 685977923. The next prime is 685977947. The reversal of 685977928 is 829779586.

It can be written as a sum of positive squares in 2 ways, for example, as 663680644 + 22297284 = 25762^2 + 4722^2 .

It is not an unprimeable number, because it can be changed into a prime (685977923) 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, 1158451 + ... + 1159042.

Almost surely, 2^685977928 is an apocalyptic number.

It is an amenable number.

685977928 is a deficient number, since it is larger than the sum of its proper divisors (634993652).

685977928 is a wasteful number, since it uses less digits than its factorization.

685977928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2317536 (or 2317532 counting only the distinct ones).

The product of its digits is 15240960, while the sum is 61.

The square root of 685977928 is about 26191.1803475903. The cubic root of 685977928 is about 881.9352759891.

The spelling of 685977928 in words is "six hundred eighty-five million, nine hundred seventy-seven thousand, nine hundred twenty-eight".