99997979 has 16 divisors (see below), whose sum is σ = 104358240. Its totient is φ = 95769600.

The previous prime is 99997973. The next prime is 99997981. The reversal of 99997979 is 97979999.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99997979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99997973) 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 in 15 ways as a sum of consecutive naturals, for example, 577937 + ... + 578109.

It is an arithmetic number, because the mean of its divisors is an integer number (6522390).

Almost surely, 2^99997979 is an apocalyptic number.

99997979 is a deficient number, since it is larger than the sum of its proper divisors (4360261).

99997979 is a wasteful number, since it uses less digits than its factorization.

99997979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430.

The product of its digits is 26040609, while the sum is 68.

The square root of 99997979 is about 9999.8989494894. The cubic root of 99997979 is about 464.1557564565.

The spelling of 99997979 in words is "ninety-nine million, nine hundred ninety-seven thousand, nine hundred seventy-nine".