18489988378 has 16 divisors (see below), whose sum is σ = 28646159616. Its totient is φ = 8941612320.

The previous prime is 18489988367. The next prime is 18489988379. The reversal of 18489988378 is 87388998481.

It is a self number, because there is not a number n which added to its sum of digits gives 18489988378.

It is not an unprimeable number, because it can be changed into a prime (18489988379) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23625 + ... + 193747.

It is an arithmetic number, because the mean of its divisors is an integer number (1790384976).

Almost surely, 2^18489988378 is an apocalyptic number.

18489988378 is a deficient number, since it is larger than the sum of its proper divisors (10156171238).

18489988378 is a wasteful number, since it uses less digits than its factorization.

18489988378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171909.

The product of its digits is 222953472, while the sum is 73.

The spelling of 18489988378 in words is "eighteen billion, four hundred eighty-nine million, nine hundred eighty-eight thousand, three hundred seventy-eight".