18722918 has 4 divisors (see below), whose sum is σ = 28084380. Its totient is φ = 9361458.

The previous prime is 18722909. The next prime is 18722941. The reversal of 18722918 is 81922781.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4680728 + ... + 4680731.

It is an arithmetic number, because the mean of its divisors is an integer number (7021095).

Almost surely, 2^18722918 is an apocalyptic number.

18722918 is a deficient number, since it is larger than the sum of its proper divisors (9361462).

18722918 is an equidigital number, since it uses as much as digits as its factorization.

18722918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9361461.

The product of its digits is 16128, while the sum is 38.

The square root of 18722918 is about 4326.9987289113. The cubic root of 18722918 is about 265.5366743564.

The spelling of 18722918 in words is "eighteen million, seven hundred twenty-two thousand, nine hundred eighteen".