205980 has 24 divisors (see below), whose sum is σ = 576912. Its totient is φ = 54912.

The previous prime is 205967. The next prime is 205981. The reversal of 205980 is 89502.

It is a self number, because there is not a number n which added to its sum of digits gives 205980.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205981) by changing a digit.

205980 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1657 + ... + 1776.

It is an arithmetic number, because the mean of its divisors is an integer number (24038).

2²⁰⁵⁹⁸⁰ is an apocalyptic number.

205980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205980 is an abundant number, since it is smaller than the sum of its proper divisors (370932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205980 is a wasteful number, since it uses less digits than its factorization.

205980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3445 (or 3443 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 205980 is about 453.8501955491. The cubic root of 205980 is about 59.0574944668.

The spelling of 205980 in words is "two hundred five thousand, nine hundred eighty".