163981979 has 12 divisors (see below), whose sum is σ = 197334000. Its totient is φ = 135708048.

The previous prime is 163981957. The next prime is 163981991. The reversal of 163981979 is 979189361.

163981979 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 163981979 - 2¹⁶ = 163916443 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

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 163981979.

It is not an unprimeable number, because it can be changed into a prime (163981999) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 56279 + ... + 59120.

It is an arithmetic number, because the mean of its divisors is an integer number (16444500).

Almost surely, 2^163981979 is an apocalyptic number.

163981979 is a deficient number, since it is larger than the sum of its proper divisors (33352021).

163981979 is a wasteful number, since it uses less digits than its factorization.

163981979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115442 (or 115435 counting only the distinct ones).

The product of its digits is 734832, while the sum is 53.

The square root of 163981979 is about 12805.5448536952. The cubic root of 163981979 is about 547.3503176369.

The spelling of 163981979 in words is "one hundred sixty-three million, nine hundred eighty-one thousand, nine hundred seventy-nine".