688654564 has 24 divisors (see below), whose sum is σ = 1374194808. Its totient is φ = 299143680.

The previous prime is 688654537. The next prime is 688654583. The reversal of 688654564 is 465456886.

It can be written as a sum of positive squares in 4 ways, for example, as 108326464 + 580328100 = 10408^2 + 24090^2 .

It is a Harshad number since it is a multiple of its sum of digits (52).

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, 388627 + ... + 390394.

It is an arithmetic number, because the mean of its divisors is an integer number (57258117).

Almost surely, 2^688654564 is an apocalyptic number.

It is an amenable number.

688654564 is a deficient number, since it is larger than the sum of its proper divisors (685540244).

688654564 is a wasteful number, since it uses less digits than its factorization.

688654564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779055 (or 779053 counting only the distinct ones).

The product of its digits is 5529600, while the sum is 52.

The square root of 688654564 is about 26242.2286401136. The cubic root of 688654564 is about 883.0808697123.

The spelling of 688654564 in words is "six hundred eighty-eight million, six hundred fifty-four thousand, five hundred sixty-four".