688774720 has 56 divisors (see below), whose sum is σ = 1736637624. Its totient is φ = 259301376.

The previous prime is 688774711. The next prime is 688774741. The reversal of 688774720 is 27477886.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 28901376 + 659873344 = 5376^2 + 25688^2 .

It is a super-2 number, since 2×688774720² = 948821229822156800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57867 + ... + 68746.

Almost surely, 2^688774720 is an apocalyptic number.

It is an amenable number.

688774720 is an abundant number, since it is smaller than the sum of its proper divisors (1047862904).

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

688774720 is a wasteful number, since it uses less digits than its factorization.

688774720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126647 (or 126637 counting only the distinct ones).

The product of its (nonzero) digits is 1053696, while the sum is 49.

The square root of 688774720 is about 26244.5179037452. The cubic root of 688774720 is about 883.1322265172.

The spelling of 688774720 in words is "six hundred eighty-eight million, seven hundred seventy-four thousand, seven hundred twenty".