18723873987 has 48 divisors (see below), whose sum is σ = 33368870080. Its totient is φ = 9852005376.

The previous prime is 18723873919. The next prime is 18723873989. The reversal of 18723873987 is 78937832781.

18723873987 is a `hidden beast` number, since 1 + 8 + 7 + 238 + 7 + 398 + 7 = 666.

It is not a de Polignac number, because 18723873987 - 2⁷ = 18723873859 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (18723873989) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 307023 + ... + 362919.

Almost surely, 2^18723873987 is an apocalyptic number.

18723873987 is a deficient number, since it is larger than the sum of its proper divisors (14644996093).

18723873987 is a wasteful number, since it uses less digits than its factorization.

18723873987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56332 (or 56329 counting only the distinct ones).

The product of its digits is 28449792, while the sum is 63.

The spelling of 18723873987 in words is "eighteen billion, seven hundred twenty-three million, eight hundred seventy-three thousand, nine hundred eighty-seven".