79781579 has 2 divisors, whose sum is σ = 79781580. Its totient is φ = 79781578.

The previous prime is 79781573. The next prime is 79781593. The reversal of 79781579 is 97518797.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 79781579 - 2⁴ = 79781563 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 79781579.

It is not a weakly prime, because it can be changed into another prime (79781573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39890789 + 39890790.

It is an arithmetic number, because the mean of its divisors is an integer number (39890790).

Almost surely, 2^79781579 is an apocalyptic number.

79781579 is a deficient number, since it is larger than the sum of its proper divisors (1).

79781579 is an equidigital number, since it uses as much as digits as its factorization.

79781579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1111320, while the sum is 53.

The square root of 79781579 is about 8932.0534593116. The cubic root of 79781579 is about 430.4944357618.

The spelling of 79781579 in words is "seventy-nine million, seven hundred eighty-one thousand, five hundred seventy-nine".