388720656 has 135 divisors (see below), whose sum is σ = 1145712477. Its totient is φ = 123027840.

The previous prime is 388720643. The next prime is 388720681. The reversal of 388720656 is 656027883.

The square root of 388720656 is 19716.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 280227600 + 108493056 = 16740^2 + 10416^2 .

It is a super-2 number, since 2×388720656² = 302207496802140672, which contains 22 as substring.

It is a nialpdrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7334326 + ... + 7334378.

Almost surely, 2^388720656 is an apocalyptic number.

388720656 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

388720656 is the 19716-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 388720656

388720656 is an abundant number, since it is smaller than the sum of its proper divisors (756991821).

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

388720656 is a wasteful number, since it uses less digits than its factorization.

388720656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The cubic root of 388720656 is about 729.8145873015.

It can be divided in two parts, 388720 and 656, that added together give a square (389376 = 624²).

The spelling of 388720656 in words is "three hundred eighty-eight million, seven hundred twenty thousand, six hundred fifty-six".