18189443973 has 16 divisors (see below), whose sum is σ = 24347473920. Its totient is φ = 12078949104.

The previous prime is 18189443971. The next prime is 18189444011. The reversal of 18189443973 is 37934498181.

It is a happy number.

It is not a de Polignac number, because 18189443973 - 2¹ = 18189443971 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18189443971) 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, 797790 + ... + 820272.

It is an arithmetic number, because the mean of its divisors is an integer number (1521717120).

Almost surely, 2^18189443973 is an apocalyptic number.

It is an amenable number.

18189443973 is a deficient number, since it is larger than the sum of its proper divisors (6158029947).

18189443973 is a wasteful number, since it uses less digits than its factorization.

18189443973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23528.

The product of its digits is 5225472, while the sum is 57.

The spelling of 18189443973 in words is "eighteen billion, one hundred eighty-nine million, four hundred forty-three thousand, nine hundred seventy-three".