79566409 has 16 divisors (see below), whose sum is σ = 92452752. Its totient is φ = 67811328.

The previous prime is 79566359. The next prime is 79566427. The reversal of 79566409 is 90466597.

It can be written as a sum of positive squares in 8 ways, for example, as 2073600 + 77492809 = 1440^2 + 8803^2 .

It is not a de Polignac number, because 79566409 - 2⁹ = 79565897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79566439) 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 15 ways as a sum of consecutive naturals, for example, 8317 + ... + 15109.

It is an arithmetic number, because the mean of its divisors is an integer number (5778297).

Almost surely, 2^79566409 is an apocalyptic number.

It is an amenable number.

79566409 is a deficient number, since it is larger than the sum of its proper divisors (12886343).

79566409 is a wasteful number, since it uses less digits than its factorization.

79566409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6876.

The product of its (nonzero) digits is 408240, while the sum is 46.

The square root of 79566409 is about 8920.0005044843. Note that the first 3 decimals coincide. The cubic root of 79566409 is about 430.1070744709.

It can be divided in two parts, 7956 and 6409, that added together give a triangular number (14365 = T₁₆₉).

The spelling of 79566409 in words is "seventy-nine million, five hundred sixty-six thousand, four hundred nine".