685787840 has 28 divisors (see below), whose sum is σ = 1633033056. Its totient is φ = 274315008.

The previous prime is 685787827. The next prime is 685787863. The reversal of 685787840 is 48787586.

It is a happy number.

It is a super-2 number, since 2×685787840² = 940609922983731200, which contains 22 as substring.

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, 1071224 + ... + 1071863.

Almost surely, 2^685787840 is an apocalyptic number.

It is an amenable number.

685787840 is an abundant number, since it is smaller than the sum of its proper divisors (947245216).

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

685787840 is a wasteful number, since it uses less digits than its factorization.

685787840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2143104 (or 2143094 counting only the distinct ones).

The product of its (nonzero) digits is 3010560, while the sum is 53.

The square root of 685787840 is about 26187.5512410000. The cubic root of 685787840 is about 881.8538055348.

The spelling of 685787840 in words is "six hundred eighty-five million, seven hundred eighty-seven thousand, eight hundred forty".