656421501 has 4 divisors (see below), whose sum is σ = 875228672. Its totient is φ = 437614332.

The previous prime is 656421487. The next prime is 656421529. The reversal of 656421501 is 105124656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 656421501 - 2¹⁴ = 656405117 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 (656411501) 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, 109403581 + ... + 109403586.

It is an arithmetic number, because the mean of its divisors is an integer number (218807168).

Almost surely, 2^656421501 is an apocalyptic number.

It is an amenable number.

656421501 is a deficient number, since it is larger than the sum of its proper divisors (218807171).

656421501 is a wasteful number, since it uses less digits than its factorization.

656421501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218807170.

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 656421501 is about 25620.7240530005. The cubic root of 656421501 is about 869.0823552054.

The spelling of 656421501 in words is "six hundred fifty-six million, four hundred twenty-one thousand, five hundred one".