656638000 has 80 divisors (see below), whose sum is σ = 1593674784. Its totient is φ = 261676800.

The previous prime is 656637979. The next prime is 656638013. The reversal of 656638000 is 836656.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 793587 + ... + 794413.

Almost surely, 2^656638000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656638000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (796837392).

656638000 is an abundant number, since it is smaller than the sum of its proper divisors (937036784).

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

656638000 is a wasteful number, since it uses less digits than its factorization.

656638000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1247 (or 1231 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 656638000 is about 25624.9487804366. The cubic root of 656638000 is about 869.1778907613.

The spelling of 656638000 in words is "six hundred fifty-six million, six hundred thirty-eight thousand".