289561 has 4 divisors (see below), whose sum is σ = 306612. Its totient is φ = 272512.

The previous prime is 289559. The next prime is 289573. The reversal of 289561 is 165982.

289561 = 380² + 381².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145161 + 144400 = 381^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 289561 - 2¹ = 289559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (289511) 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, 8500 + ... + 8533.

It is an arithmetic number, because the mean of its divisors is an integer number (76653).

2²⁸⁹⁵⁶¹ is an apocalyptic number.

289561 is the 381-st centered square number.

It is an amenable number.

289561 is a deficient number, since it is larger than the sum of its proper divisors (17051).

289561 is a wasteful number, since it uses less digits than its factorization.

289561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17050.

The product of its digits is 4320, while the sum is 31.

The square root of 289561 is about 538.1087250733. The cubic root of 289561 is about 66.1576427561.

The spelling of 289561 in words is "two hundred eighty-nine thousand, five hundred sixty-one".