18138244 has 12 divisors (see below), whose sum is σ = 31829644. Its totient is φ = 9044064.

The previous prime is 18138229. The next prime is 18138247. The reversal of 18138244 is 44283181.

It can be written as a sum of positive squares in 2 ways, for example, as 4536900 + 13601344 = 2130^2 + 3688^2 .

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (18138247) 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, 4587 + ... + 7570.

Almost surely, 2^18138244 is an apocalyptic number.

It is an amenable number.

18138244 is a deficient number, since it is larger than the sum of its proper divisors (13691400).

18138244 is a wasteful number, since it uses less digits than its factorization.

18138244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12534 (or 12532 counting only the distinct ones).

The product of its digits is 6144, while the sum is 31.

The square root of 18138244 is about 4258.9017363635. The cubic root of 18138244 is about 262.7433582937.

The spelling of 18138244 in words is "eighteen million, one hundred thirty-eight thousand, two hundred forty-four".