79591681 has 8 divisors (see below), whose sum is σ = 86889320. Its totient is φ = 72461952.

The previous prime is 79591679. The next prime is 79591693. The reversal of 79591681 is 18619597.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 25281 + 79566400 = 159^2 + 8920^2 .

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 79591681 - 2¹ = 79591679 is a prime.

It is a super-2 number, since 2×79591681² = 12669671368811522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79591081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40986 + ... + 42883.

It is an arithmetic number, because the mean of its divisors is an integer number (10861165).

Almost surely, 2^79591681 is an apocalyptic number.

It is an amenable number.

79591681 is a deficient number, since it is larger than the sum of its proper divisors (7297639).

79591681 is a wasteful number, since it uses less digits than its factorization.

79591681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83955.

The product of its digits is 136080, while the sum is 46.

The square root of 79591681 is about 8921.4169838653. The cubic root of 79591681 is about 430.1526067313.

The spelling of 79591681 in words is "seventy-nine million, five hundred ninety-one thousand, six hundred eighty-one".