656656 has 80 divisors (see below), whose sum is σ = 1749888. Its totient is φ = 230400.

The previous prime is 656651. The next prime is 656657.

656656 = 106² + 107² + ... + 146².

656656 is nontrivially palindromic in base 10.

Its product of digits (32400) is a multiple of the sum of its prime factors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656651) by changing a digit.

656656 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 15 ways as a sum of consecutive naturals, for example, 15996 + ... + 16036.

2⁶⁵⁶⁶⁵⁶ 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 656656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (874944).

656656 is an abundant number, since it is smaller than the sum of its proper divisors (1093232).

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

656656 is a wasteful number, since it uses less digits than its factorization.

656656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80 (or 74 counting only the distinct ones).

The product of its digits is 32400, while the sum is 34.

The square root of 656656 is about 810.3431371956. The cubic root of 656656 is about 86.9185832762.

The spelling of 656656 in words is "six hundred fifty-six thousand, six hundred fifty-six".