656638575841 has 2 divisors, whose sum is σ = 656638575842. Its totient is φ = 656638575840.

The previous prime is 656638575787. The next prime is 656638575917. The reversal of 656638575841 is 148575836656.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 486506250000 + 170132325841 = 697500^2 + 412471^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656638575841 is a prime.

It is not a weakly prime, because it can be changed into another prime (656638575941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328319287920 + 328319287921.

It is an arithmetic number, because the mean of its divisors is an integer number (328319287921).

Almost surely, 2^656638575841 is an apocalyptic number.

It is an amenable number.

656638575841 is a deficient number, since it is larger than the sum of its proper divisors (1).

656638575841 is an equidigital number, since it uses as much as digits as its factorization.

656638575841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152000, while the sum is 64.

The spelling of 656638575841 in words is "six hundred fifty-six billion, six hundred thirty-eight million, five hundred seventy-five thousand, eight hundred forty-one".