18363994 has 16 divisors (see below), whose sum is σ = 31632480. Its totient is φ = 7907760.

The previous prime is 18363991. The next prime is 18364001. The reversal of 18363994 is 49936381.

It is a self number, because there is not a number n which added to its sum of digits gives 18363994.

It is not an unprimeable number, because it can be changed into a prime (18363991) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 21549 + ... + 22384.

It is an arithmetic number, because the mean of its divisors is an integer number (1977030).

Almost surely, 2^18363994 is an apocalyptic number.

18363994 is a deficient number, since it is larger than the sum of its proper divisors (13268486).

18363994 is a wasteful number, since it uses less digits than its factorization.

18363994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43965.

The product of its digits is 139968, while the sum is 43.

The square root of 18363994 is about 4285.3230916700. The cubic root of 18363994 is about 263.8289085043.

The spelling of 18363994 in words is "eighteen million, three hundred sixty-three thousand, nine hundred ninety-four".