656420791 has 4 divisors (see below), whose sum is σ = 706914712. Its totient is φ = 605926872.

The previous prime is 656420719. The next prime is 656420819. The reversal of 656420791 is 197024656.

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

It is a cyclic number.

It is not a de Polignac number, because 656420791 - 2¹³ = 656412599 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 (656420491) 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, 25246941 + ... + 25246966.

It is an arithmetic number, because the mean of its divisors is an integer number (176728678).

Almost surely, 2^656420791 is an apocalyptic number.

656420791 is a deficient number, since it is larger than the sum of its proper divisors (50493921).

656420791 is a wasteful number, since it uses less digits than its factorization.

656420791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50493920.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 656420791 is about 25620.7101970262. The cubic root of 656420791 is about 869.0820418657.

The spelling of 656420791 in words is "six hundred fifty-six million, four hundred twenty thousand, seven hundred ninety-one".