646961835657 has 4 divisors (see below), whose sum is σ = 862615780880. Its totient is φ = 431307890436.

The previous prime is 646961835631. The next prime is 646961835671. The reversal of 646961835657 is 756538169646.

646961835657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 646961835657 - 2⁷ = 646961835529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646961835617) 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, 107826972607 + ... + 107826972612.

It is an arithmetic number, because the mean of its divisors is an integer number (215653945220).

Almost surely, 2^646961835657 is an apocalyptic number.

It is an amenable number.

646961835657 is a deficient number, since it is larger than the sum of its proper divisors (215653945223).

646961835657 is a wasteful number, since it uses less digits than its factorization.

646961835657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215653945222.

The product of its digits is 195955200, while the sum is 66.

The spelling of 646961835657 in words is "six hundred forty-six billion, nine hundred sixty-one million, eight hundred thirty-five thousand, six hundred fifty-seven".