688720404 has 12 divisors (see below), whose sum is σ = 1607014304. Its totient is φ = 229573464.

The previous prime is 688720387. The next prime is 688720411. The reversal of 688720404 is 404027886.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

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, 28696672 + ... + 28696695.

Almost surely, 2^688720404 is an apocalyptic number.

It is an amenable number.

688720404 is an abundant number, since it is smaller than the sum of its proper divisors (918293900).

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

688720404 is a wasteful number, since it uses less digits than its factorization.

688720404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57393374 (or 57393372 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 39.

The square root of 688720404 is about 26243.4830767564. The cubic root of 688720404 is about 883.1090116355.

The spelling of 688720404 in words is "six hundred eighty-eight million, seven hundred twenty thousand, four hundred four".