656589397 has 4 divisors (see below), whose sum is σ = 656686540. Its totient is φ = 656492256.

The previous prime is 656589359. The next prime is 656589407. The reversal of 656589397 is 793985656.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 382554481 + 274034916 = 19559^2 + 16554^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656589397 is a prime.

It is a super-2 number, since 2×656589397² = 862219272505647218, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656589497) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 37608 + ... + 52225.

It is an arithmetic number, because the mean of its divisors is an integer number (164171635).

Almost surely, 2^656589397 is an apocalyptic number.

It is an amenable number.

656589397 is a deficient number, since it is larger than the sum of its proper divisors (97143).

656589397 is an equidigital number, since it uses as much as digits as its factorization.

656589397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97142.

The product of its digits is 12247200, while the sum is 58.

The square root of 656589397 is about 25624.0004097721. Note that the first 3 decimals coincide. The cubic root of 656589397 is about 869.1564453097.

The spelling of 656589397 in words is "six hundred fifty-six million, five hundred eighty-nine thousand, three hundred ninety-seven".