18994307889 has 16 divisors (see below), whose sum is σ = 25728417792. Its totient is φ = 12462696528.

The previous prime is 18994307881. The next prime is 18994307903. The reversal of 18994307889 is 98870349981.

It is not a de Polignac number, because 18994307889 - 2³ = 18994307881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18994307881) 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, 79537 + ... + 210510.

It is an arithmetic number, because the mean of its divisors is an integer number (1608026112).

Almost surely, 2^18994307889 is an apocalyptic number.

It is an amenable number.

18994307889 is a deficient number, since it is larger than the sum of its proper divisors (6734109903).

18994307889 is a wasteful number, since it uses less digits than its factorization.

18994307889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290396.

The product of its (nonzero) digits is 31352832, while the sum is 66.

The spelling of 18994307889 in words is "eighteen billion, nine hundred ninety-four million, three hundred seven thousand, eight hundred eighty-nine".