656571785457 has 12 divisors (see below), whose sum is σ = 1018356238896. Its totient is φ = 375183877320.

The previous prime is 656571785423. The next prime is 656571785521. The reversal of 656571785457 is 754587175656.

It is not a de Polignac number, because 656571785457 - 2²⁰ = 656570736881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (656571785417) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2233237219 + ... + 2233237512.

It is an arithmetic number, because the mean of its divisors is an integer number (84863019908).

Almost surely, 2^656571785457 is an apocalyptic number.

It is an amenable number.

656571785457 is a deficient number, since it is larger than the sum of its proper divisors (361784453439).

656571785457 is a wasteful number, since it uses less digits than its factorization.

656571785457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4466474748 (or 4466474741 counting only the distinct ones).

The product of its digits is 246960000, while the sum is 66.

The spelling of 656571785457 in words is "six hundred fifty-six billion, five hundred seventy-one million, seven hundred eighty-five thousand, four hundred fifty-seven".