20655 has 24 divisors (see below), whose sum is σ = 39312. Its totient is φ = 10368.

The previous prime is 20641. The next prime is 20663. The reversal of 20655 is 55602.

20655 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 20655 - 2⁴ = 20639 is a prime.

It is a plaindrome in base 11.

It is a nialpdrome in base 12 and base 14.

It is a zygodrome in base 4 and base 14.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20655.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1207 + ... + 1223.

It is an arithmetic number, because the mean of its divisors is an integer number (1638).

2²⁰⁶⁵⁵ is an apocalyptic number.

20655 is a deficient number, since it is larger than the sum of its proper divisors (18657).

20655 is an equidigital number, since it uses as much as digits as its factorization.

20655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37 (or 25 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 20655 is about 143.7184748040. The cubic root of 20655 is about 27.4373228213.

The spelling of 20655 in words is "twenty thousand, six hundred fifty-five".