65667861681 has 32 divisors (see below), whose sum is σ = 93248610048. Its totient is φ = 40963553280.

The previous prime is 65667861653. The next prime is 65667861691. The reversal of 65667861681 is 18616876656.

It is not a de Polignac number, because 65667861681 - 2²³ = 65659473073 is a prime.

It is a super-2 number, since 2×65667861681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (65667861691) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6983475 + ... + 6992871.

It is an arithmetic number, because the mean of its divisors is an integer number (2914019064).

Almost surely, 2^65667861681 is an apocalyptic number.

It is an amenable number.

65667861681 is a deficient number, since it is larger than the sum of its proper divisors (27580748367).

65667861681 is a wasteful number, since it uses less digits than its factorization.

65667861681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10201.

The product of its digits is 17418240, while the sum is 60.

The spelling of 65667861681 in words is "sixty-five billion, six hundred sixty-seven million, eight hundred sixty-one thousand, six hundred eighty-one".