79684639 has 2 divisors, whose sum is σ = 79684640. Its totient is φ = 79684638.

The previous prime is 79684603. The next prime is 79684667. The reversal of 79684639 is 93648697.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 79684639 - 2⁷ = 79684511 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79684679) 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 as a sum of consecutive naturals, namely, 39842319 + 39842320.

It is an arithmetic number, because the mean of its divisors is an integer number (39842320).

Almost surely, 2^79684639 is an apocalyptic number.

79684639 is a deficient number, since it is larger than the sum of its proper divisors (1).

79684639 is an equidigital number, since it uses as much as digits as its factorization.

79684639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1959552, while the sum is 52.

The square root of 79684639 is about 8926.6252861874. The cubic root of 79684639 is about 430.3200051685.

The spelling of 79684639 in words is "seventy-nine million, six hundred eighty-four thousand, six hundred thirty-nine".