18139556 has 12 divisors (see below), whose sum is σ = 32419968. Its totient is φ = 8876712.

The previous prime is 18139553. The next prime is 18139573. The reversal of 18139556 is 65593181.

It is not an unprimeable number, because it can be changed into a prime (18139553) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48056 + ... + 48431.

It is an arithmetic number, because the mean of its divisors is an integer number (2701664).

Almost surely, 2^18139556 is an apocalyptic number.

It is an amenable number.

18139556 is a deficient number, since it is larger than the sum of its proper divisors (14280412).

18139556 is a wasteful number, since it uses less digits than its factorization.

18139556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96538 (or 96536 counting only the distinct ones).

The product of its digits is 32400, while the sum is 38.

The square root of 18139556 is about 4259.0557638988. The cubic root of 18139556 is about 262.7496931769.

The spelling of 18139556 in words is "eighteen million, one hundred thirty-nine thousand, five hundred fifty-six".