656440261 has 4 divisors (see below), whose sum is σ = 695054412. Its totient is φ = 617826112.

The previous prime is 656440249. The next prime is 656440297. The reversal of 656440261 is 162044656.

656440261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 310852161 + 345588100 = 17631^2 + 18590^2 .

It is a cyclic number.

It is not a de Polignac number, because 656440261 - 2⁵ = 656440229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656440061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19307050 + ... + 19307083.

It is an arithmetic number, because the mean of its divisors is an integer number (173763603).

Almost surely, 2^656440261 is an apocalyptic number.

It is an amenable number.

656440261 is a deficient number, since it is larger than the sum of its proper divisors (38614151).

656440261 is a wasteful number, since it uses less digits than its factorization.

656440261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38614150.

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 656440261 is about 25621.0901602566. The cubic root of 656440261 is about 869.0906343521.

The spelling of 656440261 in words is "six hundred fifty-six million, four hundred forty thousand, two hundred sixty-one".