18213538 has 8 divisors (see below), whose sum is σ = 31223232. Its totient is φ = 7805796.

The previous prime is 18213499. The next prime is 18213551. The reversal of 18213538 is 83531281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 650470 + ... + 650497.

It is an arithmetic number, because the mean of its divisors is an integer number (3902904).

Almost surely, 2^18213538 is an apocalyptic number.

18213538 is a deficient number, since it is larger than the sum of its proper divisors (13009694).

18213538 is a wasteful number, since it uses less digits than its factorization.

18213538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300976.

The product of its digits is 5760, while the sum is 31.

The square root of 18213538 is about 4267.7321846620. The cubic root of 18213538 is about 263.1064159950.

The spelling of 18213538 in words is "eighteen million, two hundred thirteen thousand, five hundred thirty-eight".