84999979 has 2 divisors, whose sum is σ = 84999980. Its totient is φ = 84999978.

The previous prime is 84999931. The next prime is 85000007. The reversal of 84999979 is 97999948.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 84999979 - 2¹¹ = 84997931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 84999979.

It is not a weakly prime, because it can be changed into another prime (84999379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42499989 + 42499990.

It is an arithmetic number, because the mean of its divisors is an integer number (42499990).

Almost surely, 2^84999979 is an apocalyptic number.

84999979 is a deficient number, since it is larger than the sum of its proper divisors (1).

84999979 is an equidigital number, since it uses as much as digits as its factorization.

84999979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13226976, while the sum is 64.

The square root of 84999979 is about 9219.5433184079. The cubic root of 84999979 is about 439.6829310066.

The spelling of 84999979 in words is "eighty-four million, nine hundred ninety-nine thousand, nine hundred seventy-nine".