18911979163 has 16 divisors (see below), whose sum is σ = 23690338560. Its totient is φ = 14666752800.

The previous prime is 18911979101. The next prime is 18911979173. The reversal of 18911979163 is 36197911981.

It is not a de Polignac number, because 18911979163 - 2³³ = 10322044571 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18911979173) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 565768 + ... + 598261.

It is an arithmetic number, because the mean of its divisors is an integer number (1480646160).

Almost surely, 2^18911979163 is an apocalyptic number.

18911979163 is a deficient number, since it is larger than the sum of its proper divisors (4778359397).

18911979163 is a wasteful number, since it uses less digits than its factorization.

18911979163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1164258.

The product of its digits is 734832, while the sum is 55.

The spelling of 18911979163 in words is "eighteen billion, nine hundred eleven million, nine hundred seventy-nine thousand, one hundred sixty-three".