18721668885 has 16 divisors (see below), whose sum is σ = 29964871296. Its totient is φ = 9981489728.

The previous prime is 18721668857. The next prime is 18721668913. The reversal of 18721668885 is 58886612781.

It is an interprime number because it is at equal distance from previous prime (18721668857) and next prime (18721668913).

It is a cyclic number.

It is not a de Polignac number, because 18721668885 - 2¹² = 18721664789 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166689 + ... + 255398.

It is an arithmetic number, because the mean of its divisors is an integer number (1872804456).

Almost surely, 2^18721668885 is an apocalyptic number.

18721668885 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18721668885 is a deficient number, since it is larger than the sum of its proper divisors (11243202411).

18721668885 is a wasteful number, since it uses less digits than its factorization.

18721668885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425052.

The product of its digits is 10321920, while the sum is 60.

The spelling of 18721668885 in words is "eighteen billion, seven hundred twenty-one million, six hundred sixty-eight thousand, eight hundred eighty-five".