19855 has 12 divisors (see below), whose sum is σ = 27432. Its totient is φ = 13680.

The previous prime is 19853. The next prime is 19861. The reversal of 19855 is 55891.

19855 = 55² + 56² + ... + 60².

It is not a de Polignac number, because 19855 - 2¹ = 19853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19853) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1036 + ... + 1054.

It is an arithmetic number, because the mean of its divisors is an integer number (2286).

2¹⁹⁸⁵⁵ is an apocalyptic number.

19855 is a deficient number, since it is larger than the sum of its proper divisors (7577).

19855 is a wasteful number, since it uses less digits than its factorization.

19855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54 (or 35 counting only the distinct ones).

The product of its digits is 1800, while the sum is 28.

The square root of 19855 is about 140.9077712548. The cubic root of 19855 is about 27.0784185691.

It can be divided in two parts, 198 and 55, that added together give a triangular number (253 = T₂₂).

The spelling of 19855 in words is "nineteen thousand, eight hundred fifty-five".