18509994 has 12 divisors (see below), whose sum is σ = 40105026. Its totient is φ = 6169992.

The previous prime is 18509993. The next prime is 18509999. The reversal of 18509994 is 49990581.

It can be written as a sum of positive squares in only one way, i.e., 13727025 + 4782969 = 3705^2 + 2187^2 .

It is not an unprimeable number, because it can be changed into a prime (18509993) 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 5 ways as a sum of consecutive naturals, for example, 514149 + ... + 514184.

Almost surely, 2^18509994 is an apocalyptic number.

18509994 is an abundant number, since it is smaller than the sum of its proper divisors (21595032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18509994 is a wasteful number, since it uses less digits than its factorization.

18509994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028341 (or 1028338 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 18509994 is about 4302.3242555623. The cubic root of 18509994 is about 264.5262402751.

It can be divided in two parts, 185099 and 94, that added together give a cube (185193 = 57³).

The spelling of 18509994 in words is "eighteen million, five hundred nine thousand, nine hundred ninety-four".