79642609 has 2 divisors, whose sum is σ = 79642610. Its totient is φ = 79642608.

The previous prime is 79642601. The next prime is 79642639. The reversal of 79642609 is 90624697.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76615009 + 3027600 = 8753^2 + 1740^2 .

It is a cyclic number.

It is not a de Polignac number, because 79642609 - 2³ = 79642601 is a prime.

It is not a weakly prime, because it can be changed into another prime (79642601) 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 as a sum of consecutive naturals, namely, 39821304 + 39821305.

It is an arithmetic number, because the mean of its divisors is an integer number (39821305).

Almost surely, 2^79642609 is an apocalyptic number.

It is an amenable number.

79642609 is a deficient number, since it is larger than the sum of its proper divisors (1).

79642609 is an equidigital number, since it uses as much as digits as its factorization.

79642609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 79642609 is about 8924.2707825346. The cubic root of 79642609 is about 430.2443338267.

The spelling of 79642609 in words is "seventy-nine million, six hundred forty-two thousand, six hundred nine".