66379881 has 4 divisors (see below), whose sum is σ = 88506512. Its totient is φ = 44253252.

The previous prime is 66379877. The next prime is 66379889. The reversal of 66379881 is 18897366.

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 66379881 - 2² = 66379877 is a prime.

It is a super-2 number, since 2×66379881² = 8812577203148322, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66379881.

It is not an unprimeable number, because it can be changed into a prime (66379889) 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, 11063311 + ... + 11063316.

It is an arithmetic number, because the mean of its divisors is an integer number (22126628).

Almost surely, 2^66379881 is an apocalyptic number.

It is an amenable number.

66379881 is a deficient number, since it is larger than the sum of its proper divisors (22126631).

66379881 is a wasteful number, since it uses less digits than its factorization.

66379881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22126630.

The product of its digits is 435456, while the sum is 48.

The square root of 66379881 is about 8147.3849178740. The cubic root of 66379881 is about 404.8978678605.

The spelling of 66379881 in words is "sixty-six million, three hundred seventy-nine thousand, eight hundred eighty-one".