79666681 has 8 divisors (see below), whose sum is σ = 80916480. Its totient is φ = 78423072.

The previous prime is 79666669. The next prime is 79666703. The reversal of 79666681 is 18666697.

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 79666681 - 2⁷ = 79666553 is a prime.

It is a super-2 number, since 2×79666681² = 12693560123111522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79666781) 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, 28941 + ... + 31573.

It is an arithmetic number, because the mean of its divisors is an integer number (10114560).

Almost surely, 2^79666681 is an apocalyptic number.

It is an amenable number.

79666681 is a deficient number, since it is larger than the sum of its proper divisors (1249799).

79666681 is a wasteful number, since it uses less digits than its factorization.

79666681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3095.

The product of its digits is 653184, while the sum is 49.

The square root of 79666681 is about 8925.6193622628. The cubic root of 79666681 is about 430.2876766154.

The spelling of 79666681 in words is "seventy-nine million, six hundred sixty-six thousand, six hundred eighty-one".