18366987 has 16 divisors (see below), whose sum is σ = 26248320. Its totient is φ = 11382912.

The previous prime is 18366979. The next prime is 18367001. The reversal of 18366987 is 78966381.

It is not a de Polignac number, because 18366987 - 2³ = 18366979 is a prime.

It is a super-2 number, since 2×18366987² = 674692422916338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18366587) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2064 + ... + 6402.

It is an arithmetic number, because the mean of its divisors is an integer number (1640520).

Almost surely, 2^18366987 is an apocalyptic number.

18366987 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

18366987 is a deficient number, since it is larger than the sum of its proper divisors (7881333).

18366987 is a wasteful number, since it uses less digits than its factorization.

18366987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4442.

The product of its digits is 435456, while the sum is 48.

The square root of 18366987 is about 4285.6722926514. The cubic root of 18366987 is about 263.8432408445.

The spelling of 18366987 in words is "eighteen million, three hundred sixty-six thousand, nine hundred eighty-seven".