2656642491 has 48 divisors (see below), whose sum is σ = 4105614240. Its totient is φ = 1650585600.

The previous prime is 2656642481. The next prime is 2656642589. The reversal of 2656642491 is 1942466562.

2656642491 is a `hidden beast` number, since 2 + 6 + 566 + 42 + 49 + 1 = 666.

It is not a de Polignac number, because 2656642491 - 2¹⁴ = 2656626107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2656642421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3332905 + ... + 3333701.

It is an arithmetic number, because the mean of its divisors is an integer number (85533630).

Almost surely, 2^2656642491 is an apocalyptic number.

2656642491 is a deficient number, since it is larger than the sum of its proper divisors (1448971749).

2656642491 is a wasteful number, since it uses less digits than its factorization.

2656642491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116 (or 1113 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 2656642491 is about 51542.6279015729. The cubic root of 2656642491 is about 1384.9827730961.

The spelling of 2656642491 in words is "two billion, six hundred fifty-six million, six hundred forty-two thousand, four hundred ninety-one".