18396987 has 32 divisors (see below), whose sum is σ = 29998080. Its totient is φ = 9799680.

The previous prime is 18396979. The next prime is 18397003. The reversal of 18396987 is 78969381.

It is not a de Polignac number, because 18396987 - 2³ = 18396979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18396947) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19339 + ... + 20267.

It is an arithmetic number, because the mean of its divisors is an integer number (937440).

Almost surely, 2^18396987 is an apocalyptic number.

18396987 is a deficient number, since it is larger than the sum of its proper divisors (11601093).

18396987 is a wasteful number, since it uses less digits than its factorization.

18396987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1003.

The product of its digits is 653184, while the sum is 51.

The square root of 18396987 is about 4289.1708989034. The cubic root of 18396987 is about 263.9868135057.

The spelling of 18396987 in words is "eighteen million, three hundred ninety-six thousand, nine hundred eighty-seven".