656644 has 12 divisors (see below), whose sum is σ = 1157184. Its totient is φ = 326024.

The previous prime is 656609. The next prime is 656651. The reversal of 656644 is 446656.

Its product of digits (17280) is a multiple of the sum of its prime divisors (1152).

It is an unprimeable number.

656644 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177 + ... + 1159.

It is an arithmetic number, because the mean of its divisors is an integer number (96432).

2⁶⁵⁶⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

656644 is a deficient number, since it is larger than the sum of its proper divisors (500540).

656644 is a wasteful number, since it uses less digits than its factorization.

656644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154 (or 1152 counting only the distinct ones).

The product of its digits is 17280, while the sum is 31.

The square root of 656644 is about 810.3357328910. The cubic root of 656644 is about 86.9180538111.

The spelling of 656644 in words is "six hundred fifty-six thousand, six hundred forty-four".