688633408 has 14 divisors (see below), whose sum is σ = 1366507046. Its totient is φ = 344316672.

The previous prime is 688633369. The next prime is 688633447. The reversal of 688633408 is 804336886.

It is an interprime number because it is at equal distance from previous prime (688633369) and next prime (688633447).

It can be written as a sum of positive squares in only one way, i.e., 437981184 + 250652224 = 20928^2 + 15832^2 .

It is a super-2 number, since 2×688633408² = 948431941227388928, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5379885 + ... + 5380012.

Almost surely, 2^688633408 is an apocalyptic number.

It is an amenable number.

688633408 is a deficient number, since it is larger than the sum of its proper divisors (677873638).

688633408 is a wasteful number, since it uses less digits than its factorization.

688633408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10759909 (or 10759899 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 46.

The square root of 688633408 is about 26241.8255462534. The cubic root of 688633408 is about 883.0718266442.

The spelling of 688633408 in words is "six hundred eighty-eight million, six hundred thirty-three thousand, four hundred eight".