2656686197657 has 4 divisors (see below), whose sum is σ = 2657766593040. Its totient is φ = 2655605802276.

The previous prime is 2656686197579. The next prime is 2656686197681. The reversal of 2656686197657 is 7567916866562.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2656686197657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2656686197257) 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, 540194003 + ... + 540198920.

It is an arithmetic number, because the mean of its divisors is an integer number (664441648260).

Almost surely, 2^{2656686197657} is an apocalyptic number.

It is an amenable number.

2656686197657 is a deficient number, since it is larger than the sum of its proper divisors (1080395383).

2656686197657 is a wasteful number, since it uses less digits than its factorization.

2656686197657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1080395382.

The product of its digits is 1371686400, while the sum is 74.

The spelling of 2656686197657 in words is "two trillion, six hundred fifty-six billion, six hundred eighty-six million, one hundred ninety-seven thousand, six hundred fifty-seven".