656549945656 has 64 divisors (see below), whose sum is σ = 1371135225600. Its totient is φ = 292225708800.

The previous prime is 656549945633. The next prime is 656549945657.

656549945656 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×656549945656² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656549945657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 525301 + ... + 1260571.

It is an arithmetic number, because the mean of its divisors is an integer number (21423987900).

Almost surely, 2^656549945656 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 656549945656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685567612800).

656549945656 is an abundant number, since it is smaller than the sum of its proper divisors (714585279944).

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

656549945656 is a wasteful number, since it uses less digits than its factorization.

656549945656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735500 (or 735496 counting only the distinct ones).

The product of its digits is 1049760000, while the sum is 70.

The spelling of 656549945656 in words is "six hundred fifty-six billion, five hundred forty-nine million, nine hundred forty-five thousand, six hundred fifty-six".