2656808661 has 16 divisors (see below), whose sum is σ = 3818961216. Its totient is φ = 1633220736.

The previous prime is 2656808641. The next prime is 2656808731. The reversal of 2656808661 is 1668086562.

It is a happy number.

It is not a de Polignac number, because 2656808661 - 2⁵ = 2656808629 is a prime.

It is a super-2 number, since 2×2656808661² = 14117264522329225842, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2656808661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2656808611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1426 + ... + 72908.

It is an arithmetic number, because the mean of its divisors is an integer number (238685076).

Almost surely, 2^2656808661 is an apocalyptic number.

It is an amenable number.

2656808661 is a deficient number, since it is larger than the sum of its proper divisors (1162152555).

2656808661 is a wasteful number, since it uses less digits than its factorization.

2656808661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72452.

The product of its (nonzero) digits is 829440, while the sum is 48.

The square root of 2656808661 is about 51544.2398430707. The cubic root of 2656808661 is about 1385.0116488657.

The spelling of 2656808661 in words is "two billion, six hundred fifty-six million, eight hundred eight thousand, six hundred sixty-one".