280289 has 4 divisors (see below), whose sum is σ = 282624. Its totient is φ = 277956.

The previous prime is 280277. The next prime is 280297. The reversal of 280289 is 982082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 982082 = 2 ⋅491041.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-280289 is a prime.

It is a d-powerful number, because it can be written as 2¹⁰ + 8 + 2¹⁴ + 0 + 8⁶ + 9³ .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (280219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 977 + ... + 1230.

It is an arithmetic number, because the mean of its divisors is an integer number (70656).

2²⁸⁰²⁸⁹ is an apocalyptic number.

It is an amenable number.

280289 is a deficient number, since it is larger than the sum of its proper divisors (2335).

280289 is a wasteful number, since it uses less digits than its factorization.

280289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2334.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 280289 is about 529.4232711168. The cubic root of 280289 is about 65.4438265159.

It can be divided in two parts, 28028 and 9, that multiplied together give a palindrome (252252).

The spelling of 280289 in words is "two hundred eighty thousand, two hundred eighty-nine".