656584091 has 4 divisors (see below), whose sum is σ = 656693400. Its totient is φ = 656474784.

The previous prime is 656584079. The next prime is 656584111. The reversal of 656584091 is 190485656.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656584091 is a prime.

It is a super-2 number, since 2×656584091² = 862205337108592562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656584001) 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, 45086 + ... + 57843.

It is an arithmetic number, because the mean of its divisors is an integer number (164173350).

Almost surely, 2^656584091 is an apocalyptic number.

656584091 is a deficient number, since it is larger than the sum of its proper divisors (109309).

656584091 is a wasteful number, since it uses less digits than its factorization.

656584091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109308.

The product of its (nonzero) digits is 259200, while the sum is 44.

The square root of 656584091 is about 25623.8968738168. The cubic root of 656584091 is about 869.1541040410.

The spelling of 656584091 in words is "six hundred fifty-six million, five hundred eighty-four thousand, ninety-one".