18939398 has 8 divisors (see below), whose sum is σ = 28444608. Its totient is φ = 9457864.

The previous prime is 18939379. The next prime is 18939421. The reversal of 18939398 is 89393981.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3761 + ... + 7212.

It is an arithmetic number, because the mean of its divisors is an integer number (3555576).

Almost surely, 2^18939398 is an apocalyptic number.

18939398 is a deficient number, since it is larger than the sum of its proper divisors (9505210).

18939398 is a wasteful number, since it uses less digits than its factorization.

18939398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11838.

The product of its digits is 419904, while the sum is 50.

The square root of 18939398 is about 4351.9418654205. The cubic root of 18939398 is about 266.5561601152.

The spelling of 18939398 in words is "eighteen million, nine hundred thirty-nine thousand, three hundred ninety-eight".