65640793931 has 4 divisors (see below), whose sum is σ = 65727050664. Its totient is φ = 65554537200.

The previous prime is 65640793921. The next prime is 65640793943. The reversal of 65640793931 is 13939704656.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 65640793931 - 2¹⁰ = 65640792907 is a prime.

It is a super-2 number, since 2×65640793931² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65640793921) 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, 43127225 + ... + 43128746.

It is an arithmetic number, because the mean of its divisors is an integer number (16431762666).

Almost surely, 2^65640793931 is an apocalyptic number.

65640793931 is a deficient number, since it is larger than the sum of its proper divisors (86256733).

65640793931 is an equidigital number, since it uses as much as digits as its factorization.

65640793931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86256732.

The product of its (nonzero) digits is 3674160, while the sum is 53.

The spelling of 65640793931 in words is "sixty-five billion, six hundred forty million, seven hundred ninety-three thousand, nine hundred thirty-one".