99999879 has 32 divisors (see below), whose sum is σ = 157925376. Its totient is φ = 55100640.

The previous prime is 99999847. The next prime is 99999931. The reversal of 99999879 is 97899999.

It is not a de Polignac number, because 99999879 - 2⁵ = 99999847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99999839) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69364 + ... + 70790.

It is an arithmetic number, because the mean of its divisors is an integer number (4935168).

Almost surely, 2^99999879 is an apocalyptic number.

99999879 is a deficient number, since it is larger than the sum of its proper divisors (57925497).

99999879 is a wasteful number, since it uses less digits than its factorization.

99999879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555.

The product of its digits is 29760696, while the sum is 69.

The square root of 99999879 is about 9999.9939499982. The cubic root of 99999879 is about 464.1586961505.

The spelling of 99999879 in words is "ninety-nine million, nine hundred ninety-nine thousand, eight hundred seventy-nine".