656737920 has 192 divisors, whose sum is σ = 2290134600. Its totient is φ = 173408256.

The previous prime is 656737889. The next prime is 656737937. The reversal of 656737920 is 29737656.

It can be written as a sum of positive squares in 4 ways, for example, as 260887104 + 395850816 = 16152^2 + 19896^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 650376 + ... + 651384.

Almost surely, 2^656737920 is an apocalyptic number.

656737920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 656737920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1145067300).

656737920 is an abundant number, since it is smaller than the sum of its proper divisors (1633396680).

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

656737920 is a wasteful number, since it uses less digits than its factorization.

656737920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1147 (or 1132 counting only the distinct ones).

The product of its (nonzero) digits is 476280, while the sum is 45.

The square root of 656737920 is about 25626.8983687063. The cubic root of 656737920 is about 869.2219758584.

The spelling of 656737920 in words is "six hundred fifty-six million, seven hundred thirty-seven thousand, nine hundred twenty".