18999994 has 24 divisors (see below), whose sum is σ = 31358880. Its totient is φ = 8628048.

The previous prime is 18999991. The next prime is 18999997. The reversal of 18999994 is 49999981.

It is an interprime number because it is at equal distance from previous prime (18999991) and next prime (18999997).

It is not an unprimeable number, because it can be changed into a prime (18999991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22227 + ... + 23065.

It is an arithmetic number, because the mean of its divisors is an integer number (1306620).

Almost surely, 2^18999994 is an apocalyptic number.

18999994 is a deficient number, since it is larger than the sum of its proper divisors (12358886).

18999994 is a wasteful number, since it uses less digits than its factorization.

18999994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934 (or 921 counting only the distinct ones).

The product of its digits is 1889568, while the sum is 58.

The square root of 18999994 is about 4358.8982552934. The cubic root of 18999994 is about 266.8401367838.

The spelling of 18999994 in words is "eighteen million, nine hundred ninety-nine thousand, nine hundred ninety-four".