18897855 has 32 divisors (see below), whose sum is σ = 31401216. Its totient is φ = 9698304.

The previous prime is 18897847. The next prime is 18897859. The reversal of 18897855 is 55879881.

It is not a de Polignac number, because 18897855 - 2³ = 18897847 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18897798 and 18897807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18897859) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53359 + ... + 53711.

It is an arithmetic number, because the mean of its divisors is an integer number (981288).

Almost surely, 2^18897855 is an apocalyptic number.

18897855 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18897855 is a deficient number, since it is larger than the sum of its proper divisors (12503361).

18897855 is a wasteful number, since it uses less digits than its factorization.

18897855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487.

The product of its digits is 806400, while the sum is 51.

The square root of 18897855 is about 4347.1663184194. The cubic root of 18897855 is about 266.3611231358.

The spelling of 18897855 in words is "eighteen million, eight hundred ninety-seven thousand, eight hundred fifty-five".