20189855 has 16 divisors (see below), whose sum is σ = 27793920. Its totient is φ = 13792032.

The previous prime is 20189849. The next prime is 20189857. The reversal of 20189855 is 55898102.

It is a cyclic number.

It is not a de Polignac number, because 20189855 - 2⁸ = 20189599 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20189857) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9806 + ... + 11684.

It is an arithmetic number, because the mean of its divisors is an integer number (1737120).

Almost surely, 2^20189855 is an apocalyptic number.

20189855 is a deficient number, since it is larger than the sum of its proper divisors (7604065).

20189855 is a wasteful number, since it uses less digits than its factorization.

20189855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2198.

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 20189855 is about 4493.3122526706. The cubic root of 20189855 is about 272.2979676921.

The spelling of 20189855 in words is "twenty million, one hundred eighty-nine thousand, eight hundred fifty-five".