688400636 has 24 divisors (see below), whose sum is σ = 1501965696. Its totient is φ = 268207920.

The previous prime is 688400627. The next prime is 688400653. The reversal of 688400636 is 636004886.

It is a junction number, because it is equal to n+sod(n) for n = 688400593 and 688400602.

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, 1117226 + ... + 1117841.

It is an arithmetic number, because the mean of its divisors is an integer number (62581904).

Almost surely, 2^688400636 is an apocalyptic number.

It is an amenable number.

688400636 is an abundant number, since it is smaller than the sum of its proper divisors (813565060).

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

688400636 is a wasteful number, since it uses less digits than its factorization.

688400636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2235089 (or 2235087 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 41.

The square root of 688400636 is about 26237.3900378830. The cubic root of 688400636 is about 882.9723167271.

The spelling of 688400636 in words is "six hundred eighty-eight million, four hundred thousand, six hundred thirty-six".