656661000 has 64 divisors (see below), whose sum is σ = 2048791680. Its totient is φ = 175108800.

The previous prime is 656660999. The next prime is 656661059. The reversal of 656661000 is 166656.

It is a Harshad number since it is a multiple of its sum of digits (30).

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 15 ways as a sum of consecutive naturals, for example, 106444 + ... + 112443.

It is an arithmetic number, because the mean of its divisors is an integer number (32012370).

Almost surely, 2^656661000 is an apocalyptic number.

656661000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

656661000 is an abundant number, since it is smaller than the sum of its proper divisors (1392130680).

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

656661000 is a wasteful number, since it uses less digits than its factorization.

656661000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218911 (or 218897 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 656661000 is about 25625.3975578917. The cubic root of 656661000 is about 869.1880388480.

It can be divided in two parts, 65666 and 1000, that added together give a palindrome (66666).

The spelling of 656661000 in words is "six hundred fifty-six million, six hundred sixty-one thousand".