656501616601 has 4 divisors (see below), whose sum is σ = 695119358772. Its totient is φ = 617883874432.

The previous prime is 656501616577. The next prime is 656501616619. The reversal of 656501616601 is 106616105656.

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 266999558400 + 389502058201 = 516720^2 + 624101^2 .

It is a cyclic number.

It is not a de Polignac number, because 656501616601 - 2²⁵ = 656468062169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656501616691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19308871060 + ... + 19308871093.

It is an arithmetic number, because the mean of its divisors is an integer number (173779839693).

Almost surely, 2^656501616601 is an apocalyptic number.

It is an amenable number.

656501616601 is a deficient number, since it is larger than the sum of its proper divisors (38617742171).

656501616601 is a wasteful number, since it uses less digits than its factorization.

656501616601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38617742170.

The product of its (nonzero) digits is 194400, while the sum is 43.

The spelling of 656501616601 in words is "six hundred fifty-six billion, five hundred one million, six hundred sixteen thousand, six hundred one".