289921 has 4 divisors (see below), whose sum is σ = 305200. Its totient is φ = 274644.

The previous prime is 289897. The next prime is 289937. The reversal of 289921 is 129982.

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.

It is a cyclic number.

It is not a de Polignac number, because 289921 - 2⁵ = 289889 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 289921.

It is not an unprimeable number, because it can be changed into a prime (289951) by changing a digit.

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, 7611 + ... + 7648.

It is an arithmetic number, because the mean of its divisors is an integer number (76300).

2²⁸⁹⁹²¹ is an apocalyptic number.

It is an amenable number.

289921 is a deficient number, since it is larger than the sum of its proper divisors (15279).

289921 is a wasteful number, since it uses less digits than its factorization.

289921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15278.

The product of its digits is 2592, while the sum is 31.

The square root of 289921 is about 538.4431260588. The cubic root of 289921 is about 66.1850484819.

The spelling of 289921 in words is "two hundred eighty-nine thousand, nine hundred twenty-one".