18939538 has 8 divisors (see below), whose sum is σ = 28590732. Its totient is φ = 9409296.

The previous prime is 18939533. The next prime is 18939551. The reversal of 18939538 is 83593981.

It can be written as a sum of positive squares in 2 ways, for example, as 15264649 + 3674889 = 3907^2 + 1917^2 .

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

It is not an unprimeable number, because it can be changed into a prime (18939533) 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, 29845 + ... + 30472.

Almost surely, 2^18939538 is an apocalyptic number.

18939538 is a deficient number, since it is larger than the sum of its proper divisors (9651194).

18939538 is a wasteful number, since it uses less digits than its factorization.

18939538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60476.

The product of its digits is 233280, while the sum is 46.

The square root of 18939538 is about 4351.9579501645. The cubic root of 18939538 is about 266.5568169079.

The spelling of 18939538 in words is "eighteen million, nine hundred thirty-nine thousand, five hundred thirty-eight".