18139090 has 24 divisors (see below), whose sum is σ = 33165540. Its totient is φ = 7142784.

The previous prime is 18139087. The next prime is 18139103. The reversal of 18139090 is 9093181.

It can be written as a sum of positive squares in 6 ways, for example, as 6517809 + 11621281 = 2553^2 + 3409^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79096 + ... + 79324.

Almost surely, 2^18139090 is an apocalyptic number.

18139090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18139090 is a deficient number, since it is larger than the sum of its proper divisors (15026450).

18139090 is an equidigital number, since it uses as much as digits as its factorization.

18139090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 18139090 is about 4259.0010565859. The cubic root of 18139090 is about 262.7474431695.

The spelling of 18139090 in words is "eighteen million, one hundred thirty-nine thousand, ninety".