18789693021 has 24 divisors (see below), whose sum is σ = 30628971360. Its totient is φ = 10995012000.

The previous prime is 18789693019. The next prime is 18789693049. The reversal of 18789693021 is 12039698781.

It is not a de Polignac number, because 18789693021 - 2¹ = 18789693019 is a prime.

It is a super-2 number, since 2×18789693021² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18789693121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3269455 + ... + 3275196.

It is an arithmetic number, because the mean of its divisors is an integer number (1276207140).

Almost surely, 2^18789693021 is an apocalyptic number.

18789693021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18789693021 is a deficient number, since it is larger than the sum of its proper divisors (11839278339).

18789693021 is a wasteful number, since it uses less digits than its factorization.

18789693021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6544697 (or 6544694 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 18789693021 in words is "eighteen billion, seven hundred eighty-nine million, six hundred ninety-three thousand, twenty-one".