18138506 has 16 divisors (see below), whose sum is σ = 27675648. Its totient is φ = 8914800.

The previous prime is 18138499. The next prime is 18138509. The reversal of 18138506 is 60583181.

It is not an unprimeable number, because it can be changed into a prime (18138509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39116 + ... + 39576.

It is an arithmetic number, because the mean of its divisors is an integer number (1729728).

Almost surely, 2^18138506 is an apocalyptic number.

18138506 is a deficient number, since it is larger than the sum of its proper divisors (9537142).

18138506 is a wasteful number, since it uses less digits than its factorization.

18138506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 18138506 is about 4258.9324953561. The cubic root of 18138506 is about 262.7446233634.

The spelling of 18138506 in words is "eighteen million, one hundred thirty-eight thousand, five hundred six".