665131024881 has 16 divisors (see below), whose sum is σ = 988861213120. Its totient is φ = 441853820640.

The previous prime is 665131024871. The next prime is 665131024913. The reversal of 665131024881 is 188420131566.

665131024881 is a `hidden beast` number, since 6 + 6 + 513 + 10 + 2 + 48 + 81 = 666.

665131024881 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 665131024881 - 2²⁵ = 665097470449 is a prime.

It is a super-2 number, since 2×665131024881² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (665131024861) 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, 43516180 + ... + 43531461.

It is an arithmetic number, because the mean of its divisors is an integer number (61803825820).

Almost surely, 2^665131024881 is an apocalyptic number.

It is an amenable number.

665131024881 is a deficient number, since it is larger than the sum of its proper divisors (323730188239).

665131024881 is a wasteful number, since it uses less digits than its factorization.

665131024881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87047933 (or 87047927 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 665131024881 in words is "six hundred sixty-five billion, one hundred thirty-one million, twenty-four thousand, eight hundred eighty-one".