288021 has 16 divisors (see below), whose sum is σ = 419840. Its totient is φ = 174960.

The previous prime is 288007. The next prime is 288023. The reversal of 288021 is 120882.

288021 = 114² + 115² + ... + 132².

It is not a de Polignac number, because 288021 - 2¹⁴ = 271637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (288023) 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, 1686 + ... + 1848.

It is an arithmetic number, because the mean of its divisors is an integer number (26240).

2²⁸⁸⁰²¹ is an apocalyptic number.

It is an amenable number.

288021 is a deficient number, since it is larger than the sum of its proper divisors (131819).

288021 is a wasteful number, since it uses less digits than its factorization.

288021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216.

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 288021 is about 536.6758798381. The cubic root of 288021 is about 66.0401500424.

The spelling of 288021 in words is "two hundred eighty-eight thousand, twenty-one".