66384681 has 8 divisors (see below), whose sum is σ = 96559584. Its totient is φ = 40233120.

The previous prime is 66384679. The next prime is 66384707. The reversal of 66384681 is 18648366.

It is a happy number.

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

It is not a de Polignac number, because 66384681 - 2¹ = 66384679 is a prime.

It is a super-2 number, since 2×66384681² = 8813851742943522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66384611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1005796 + ... + 1005861.

It is an arithmetic number, because the mean of its divisors is an integer number (12069948).

Almost surely, 2^66384681 is an apocalyptic number.

It is an amenable number.

66384681 is a deficient number, since it is larger than the sum of its proper divisors (30174903).

66384681 is a wasteful number, since it uses less digits than its factorization.

66384681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2011671.

The product of its digits is 165888, while the sum is 42.

The square root of 66384681 is about 8147.6794855959. The cubic root of 66384681 is about 404.9076271575.

The spelling of 66384681 in words is "sixty-six million, three hundred eighty-four thousand, six hundred eighty-one".