79666405 has 24 divisors (see below), whose sum is σ = 119767032. Its totient is φ = 50424192.

The previous prime is 79666399. The next prime is 79666409. The reversal of 79666405 is 50466697.

It can be written as a sum of positive squares in 4 ways, for example, as 16654561 + 63011844 = 4081^2 + 7938^2 .

It is not a de Polignac number, because 79666405 - 2³ = 79666397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79666409) 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 23 ways as a sum of consecutive naturals, for example, 9322 + ... + 15691.

It is an arithmetic number, because the mean of its divisors is an integer number (4990293).

Almost surely, 2^79666405 is an apocalyptic number.

It is an amenable number.

79666405 is a deficient number, since it is larger than the sum of its proper divisors (40100627).

79666405 is a wasteful number, since it uses less digits than its factorization.

79666405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25045 (or 25038 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 79666405 is about 8925.6039011374. The cubic root of 79666405 is about 430.2871797137.

The spelling of 79666405 in words is "seventy-nine million, six hundred sixty-six thousand, four hundred five".