656051661 has 24 divisors (see below), whose sum is σ = 963317784. Its totient is φ = 430185600.

The previous prime is 656051633. The next prime is 656051677. The reversal of 656051661 is 166150656.

It can be written as a sum of positive squares in 4 ways, for example, as 65853225 + 590198436 = 8115^2 + 24294^2 .

It is not a de Polignac number, because 656051661 - 2⁶ = 656051597 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656051681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 140415 + ... + 145011.

It is an arithmetic number, because the mean of its divisors is an integer number (40138241).

Almost surely, 2^656051661 is an apocalyptic number.

It is an amenable number.

656051661 is a deficient number, since it is larger than the sum of its proper divisors (307266123).

656051661 is a wasteful number, since it uses less digits than its factorization.

656051661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4861 (or 4858 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 656051661 is about 25613.5054414658. The cubic root of 656051661 is about 868.9191055243.

The spelling of 656051661 in words is "six hundred fifty-six million, fifty-one thousand, six hundred sixty-one".