18785991844 has 9 divisors (see below), whose sum is σ = 32875965451. Its totient is φ = 9392858860.

The previous prime is 18785991817. The next prime is 18785991853. The reversal of 18785991844 is 44819958781.

The square root of 18785991844 is 137062.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 239859 + ... + 308389.

Almost surely, 2^18785991844 is an apocalyptic number.

18785991844 is the 137062-nd square number.

It is an amenable number.

18785991844 is a deficient number, since it is larger than the sum of its proper divisors (14089973607).

18785991844 is an frugal number, since it uses more digits than its factorization.

18785991844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137066 (or 68533 counting only the distinct ones).

The product of its digits is 23224320, while the sum is 64.

Multiplying 18785991844 by its sum of digits (64), we get a square (1202303478016 = 1096496²).

The spelling of 18785991844 in words is "eighteen billion, seven hundred eighty-five million, nine hundred ninety-one thousand, eight hundred forty-four".