657315661 has 4 divisors (see below), whose sum is σ = 678519424. Its totient is φ = 636111900.

The previous prime is 657315623. The next prime is 657315683. The reversal of 657315661 is 166513756.

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 not a de Polignac number, because 657315661 - 2²⁷ = 523097933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (657315611) 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, 10601835 + ... + 10601896.

It is an arithmetic number, because the mean of its divisors is an integer number (169629856).

Almost surely, 2^657315661 is an apocalyptic number.

It is an amenable number.

657315661 is a deficient number, since it is larger than the sum of its proper divisors (21203763).

657315661 is a wasteful number, since it uses less digits than its factorization.

657315661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21203762.

The product of its digits is 113400, while the sum is 40.

The square root of 657315661 is about 25638.1680507793. The cubic root of 657315661 is about 869.4767898263.

The spelling of 657315661 in words is "six hundred fifty-seven million, three hundred fifteen thousand, six hundred sixty-one".