18939994 has 8 divisors (see below), whose sum is σ = 29645280. Its totient is φ = 9058236.

The previous prime is 18939983. The next prime is 18939997. The reversal of 18939994 is 49993981.

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 (18939997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 205824 + ... + 205915.

It is an arithmetic number, because the mean of its divisors is an integer number (3705660).

Almost surely, 2^18939994 is an apocalyptic number.

18939994 is a deficient number, since it is larger than the sum of its proper divisors (10705286).

18939994 is a wasteful number, since it uses less digits than its factorization.

18939994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411764.

The product of its digits is 629856, while the sum is 52.

The square root of 18939994 is about 4352.0103400612. The cubic root of 18939994 is about 266.5589561528.

The spelling of 18939994 in words is "eighteen million, nine hundred thirty-nine thousand, nine hundred ninety-four".