108991979 has 4 divisors (see below), whose sum is σ = 109030584. Its totient is φ = 108953376.

The previous prime is 108991957. The next prime is 108991997. The reversal of 108991979 is 979199801.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 108991979 - 2⁸ = 108991723 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 108991979.

It is not an unprimeable number, because it can be changed into a prime (108991279) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14702 + ... + 20835.

It is an arithmetic number, because the mean of its divisors is an integer number (27257646).

Almost surely, 2^108991979 is an apocalyptic number.

108991979 is a deficient number, since it is larger than the sum of its proper divisors (38605).

108991979 is an equidigital number, since it uses as much as digits as its factorization.

108991979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38604.

The product of its (nonzero) digits is 367416, while the sum is 53.

The square root of 108991979 is about 10439.9223656117. The cubic root of 108991979 is about 477.6739006407.

The spelling of 108991979 in words is "one hundred eight million, nine hundred ninety-one thousand, nine hundred seventy-nine".