258021 has 6 divisors (see below), whose sum is σ = 372710. Its totient is φ = 172008.

The previous prime is 258019. The next prime is 258023. The reversal of 258021 is 120852.

It is an interprime number because it is at equal distance from previous prime (258019) and next prime (258023).

It can be written as a sum of positive squares in only one way, i.e., 245025 + 12996 = 495^2 + 114^2 .

It is not a de Polignac number, because 258021 - 2¹ = 258019 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 257985 and 258003.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 258021.

It is not an unprimeable number, because it can be changed into a prime (258023) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14326 + ... + 14343.

2²⁵⁸⁰²¹ is an apocalyptic number.

It is an amenable number.

258021 is a deficient number, since it is larger than the sum of its proper divisors (114689).

258021 is a wasteful number, since it uses less digits than its factorization.

258021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28675 (or 28672 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 258021 is about 507.9576754022. The cubic root of 258021 is about 63.6626947929.

Adding to 258021 its reverse (120852), we get a palindrome (378873).

It can be divided in two parts, 2580 and 21, that added together give a square (2601 = 51²).

The spelling of 258021 in words is "two hundred fifty-eight thousand, twenty-one".