656213215571 has 2 divisors, whose sum is σ = 656213215572. Its totient is φ = 656213215570.

The previous prime is 656213215549. The next prime is 656213215573. The reversal of 656213215571 is 175512312656.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-656213215571 is a prime.

It is a Sophie Germain prime.

Together with 656213215573, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (656213215573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 328106607785 + 328106607786.

It is an arithmetic number, because the mean of its divisors is an integer number (328106607786).

Almost surely, 2^656213215571 is an apocalyptic number.

656213215571 is a deficient number, since it is larger than the sum of its proper divisors (1).

656213215571 is an equidigital number, since it uses as much as digits as its factorization.

656213215571 is an evil number, because the sum of its binary digits is even.

The product of its digits is 378000, while the sum is 44.

The spelling of 656213215571 in words is "six hundred fifty-six billion, two hundred thirteen million, two hundred fifteen thousand, five hundred seventy-one".