79663581 has 20 divisors (see below), whose sum is σ = 126006012. Its totient is φ = 49984128.

The previous prime is 79663579. The next prime is 79663601. The reversal of 79663581 is 18536697.

It is a happy number.

79663581 is a `hidden beast` number, since 7 + 9 + 6 + 63 + 581 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 34222500 + 45441081 = 5850^2 + 6741^2 .

It is not a de Polignac number, because 79663581 - 2¹ = 79663579 is a prime.

It is a super-2 number, since 2×79663581² = 12692572275487122, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79663501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 27550 + ... + 30303.

Almost surely, 2^79663581 is an apocalyptic number.

It is an amenable number.

79663581 is a deficient number, since it is larger than the sum of its proper divisors (46342431).

79663581 is a wasteful number, since it uses less digits than its factorization.

79663581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57882 (or 57873 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 79663581 is about 8925.4457031568. The cubic root of 79663581 is about 430.2820954068.

The spelling of 79663581 in words is "seventy-nine million, six hundred sixty-three thousand, five hundred eighty-one".