18543994 has 8 divisors (see below), whose sum is σ = 31789728. Its totient is φ = 7947420.

The previous prime is 18543989. The next prime is 18544007. The reversal of 18543994 is 49934581.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 18543994.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 662272 + ... + 662299.

It is an arithmetic number, because the mean of its divisors is an integer number (3973716).

Almost surely, 2^18543994 is an apocalyptic number.

18543994 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

18543994 is a deficient number, since it is larger than the sum of its proper divisors (13245734).

18543994 is a wasteful number, since it uses less digits than its factorization.

18543994 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1324580.

The product of its digits is 155520, while the sum is 43.

The square root of 18543994 is about 4306.2737952898. The cubic root of 18543994 is about 264.6881058234.

The spelling of 18543994 in words is "eighteen million, five hundred forty-three thousand, nine hundred ninety-four".