163971978 has 24 divisors (see below), whose sum is σ = 332026368. Its totient is φ = 53985192.

The previous prime is 163971961. The next prime is 163971979. The reversal of 163971978 is 879179361.

It is a self number, because there is not a number n which added to its sum of digits gives 163971978.

It is not an unprimeable number, because it can be changed into a prime (163971979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39351 + ... + 43317.

It is an arithmetic number, because the mean of its divisors is an integer number (13834432).

Almost surely, 2^163971978 is an apocalyptic number.

163971978 is an abundant number, since it is smaller than the sum of its proper divisors (168054390).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

163971978 is an equidigital number, since it uses as much as digits as its factorization.

163971978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4138 (or 4055 counting only the distinct ones).

The product of its digits is 571536, while the sum is 51.

The square root of 163971978 is about 12805.1543528378. The cubic root of 163971978 is about 547.3391900690.

The spelling of 163971978 in words is "one hundred sixty-three million, nine hundred seventy-one thousand, nine hundred seventy-eight".