18919718931 has 16 divisors (see below), whose sum is σ = 26808772608. Its totient is φ = 11827382400.

The previous prime is 18919718887. The next prime is 18919718957. The reversal of 18919718931 is 13981791981.

It is not a de Polignac number, because 18919718931 - 2⁷ = 18919718803 is a prime.

It is a super-2 number, since 2×18919718931² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18919713931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 670635 + ... + 698276.

It is an arithmetic number, because the mean of its divisors is an integer number (1675548288).

Almost surely, 2^18919718931 is an apocalyptic number.

18919718931 is a deficient number, since it is larger than the sum of its proper divisors (7889053677).

18919718931 is a wasteful number, since it uses less digits than its factorization.

18919718931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1369202.

The product of its digits is 979776, while the sum is 57.

The spelling of 18919718931 in words is "eighteen billion, nine hundred nineteen million, seven hundred eighteen thousand, nine hundred thirty-one".