18319918 has 8 divisors (see below), whose sum is σ = 27570312. Its totient is φ = 9129816.

The previous prime is 18319901. The next prime is 18319919. The reversal of 18319918 is 81991381.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18319919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14305 + ... + 15532.

It is an arithmetic number, because the mean of its divisors is an integer number (3446289).

Almost surely, 2^18319918 is an apocalyptic number.

18319918 is a deficient number, since it is larger than the sum of its proper divisors (9250394).

18319918 is a wasteful number, since it uses less digits than its factorization.

18319918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30146.

The product of its digits is 15552, while the sum is 40.

The square root of 18319918 is about 4280.1773327749. The cubic root of 18319918 is about 263.6176647207.

The spelling of 18319918 in words is "eighteen million, three hundred nineteen thousand, nine hundred eighteen".