18904855 has 4 divisors (see below), whose sum is σ = 22685832. Its totient is φ = 15123880.

The previous prime is 18904849. The next prime is 18904859. The reversal of 18904855 is 55840981.

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

It is a de Polignac number, because none of the positive numbers 2^k-18904855 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18904859) 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, 1890481 + ... + 1890490.

It is an arithmetic number, because the mean of its divisors is an integer number (5671458).

Almost surely, 2^18904855 is an apocalyptic number.

18904855 is a deficient number, since it is larger than the sum of its proper divisors (3780977).

18904855 is an equidigital number, since it uses as much as digits as its factorization.

18904855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3780976.

The product of its (nonzero) digits is 57600, while the sum is 40.

The square root of 18904855 is about 4347.9713660511. The cubic root of 18904855 is about 266.3940068977.

The spelling of 18904855 in words is "eighteen million, nine hundred four thousand, eight hundred fifty-five".