289305 has 16 divisors (see below), whose sum is σ = 514560. Its totient is φ = 154224.

The previous prime is 289297. The next prime is 289309. The reversal of 289305 is 503982.

289305 = 15² + 16² + ... + 95².

It is not a de Polignac number, because 289305 - 2³ = 289297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (289309) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 937 + ... + 1206.

It is an arithmetic number, because the mean of its divisors is an integer number (32160).

2²⁸⁹³⁰⁵ is an apocalyptic number.

It is an amenable number.

289305 is a deficient number, since it is larger than the sum of its proper divisors (225255).

289305 is a wasteful number, since it uses less digits than its factorization.

289305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2157 (or 2151 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 289305 is about 537.8708023308. The cubic root of 289305 is about 66.1381404174.

The spelling of 289305 in words is "two hundred eighty-nine thousand, three hundred five".