18138986 has 16 divisors (see below), whose sum is σ = 27808704. Its totient is φ = 8871744.

The previous prime is 18138971. The next prime is 18138997. The reversal of 18138986 is 68983181.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18275 + ... + 19241.

It is an arithmetic number, because the mean of its divisors is an integer number (1738044).

Almost surely, 2^18138986 is an apocalyptic number.

18138986 is a deficient number, since it is larger than the sum of its proper divisors (9669718).

18138986 is a wasteful number, since it uses less digits than its factorization.

18138986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1165.

The product of its digits is 82944, while the sum is 44.

The square root of 18138986 is about 4258.9888471326. The cubic root of 18138986 is about 262.7469410167.

The spelling of 18138986 in words is "eighteen million, one hundred thirty-eight thousand, nine hundred eighty-six".