205280 has 24 divisors (see below), whose sum is σ = 485352. Its totient is φ = 82048.

The previous prime is 205267. The next prime is 205297. The reversal of 205280 is 82502.

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

205280 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 482 + ... + 801.

It is an arithmetic number, because the mean of its divisors is an integer number (20223).

2²⁰⁵²⁸⁰ is an apocalyptic number.

205280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205280 is an abundant number, since it is smaller than the sum of its proper divisors (280072).

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

205280 is a wasteful number, since it uses less digits than its factorization.

205280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1298 (or 1290 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 205280 is about 453.0783596686. The cubic root of 205280 is about 58.9905184419.

Subtracting from 205280 its product of nonzero digits (160), we obtain a triangular number (205120 = T₆₄₀).

Adding to 205280 its reverse (82502), we get a palindrome (287782).

The spelling of 205280 in words is "two hundred five thousand, two hundred eighty".