18573994387 has 16 divisors (see below), whose sum is σ = 20327856640. Its totient is φ = 16868116512.

The previous prime is 18573994349. The next prime is 18573994393. The reversal of 18573994387 is 78349937581.

It is not a de Polignac number, because 18573994387 - 2¹⁵ = 18573961619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18573994987) 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, 258688 + ... + 322594.

It is an arithmetic number, because the mean of its divisors is an integer number (1270491040).

Almost surely, 2^18573994387 is an apocalyptic number.

18573994387 is a deficient number, since it is larger than the sum of its proper divisors (1753862253).

18573994387 is a wasteful number, since it uses less digits than its factorization.

18573994387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64282.

The product of its digits is 45722880, while the sum is 64.

It can be divided in two parts, 185739 and 94387, that added together give a triangular number (280126 = T₇₄₈).

The spelling of 18573994387 in words is "eighteen billion, five hundred seventy-three million, nine hundred ninety-four thousand, three hundred eighty-seven".