66215660131 has 8 divisors (see below), whose sum is σ = 66844714320. Its totient is φ = 65589485568.

The previous prime is 66215660123. The next prime is 66215660167. The reversal of 66215660131 is 13106651266.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66215660131 - 2³ = 66215660123 is a prime.

It is a super-2 number, since 2×66215660131² (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 (66215660111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 673686 + ... + 765691.

It is an arithmetic number, because the mean of its divisors is an integer number (8355589290).

Almost surely, 2^66215660131 is an apocalyptic number.

66215660131 is a deficient number, since it is larger than the sum of its proper divisors (629054189).

66215660131 is a wasteful number, since it uses less digits than its factorization.

66215660131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1439813.

The product of its (nonzero) digits is 38880, while the sum is 37.

The spelling of 66215660131 in words is "sixty-six billion, two hundred fifteen million, six hundred sixty thousand, one hundred thirty-one".