258561 has 6 divisors (see below), whose sum is σ = 373490. Its totient is φ = 172368.

The previous prime is 258551. The next prime is 258563. The reversal of 258561 is 165852.

It can be written as a sum of positive squares in only one way, i.e., 207936 + 50625 = 456^2 + 225^2 .

It is a de Polignac number, because none of the positive numbers 2^k-258561 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

258561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (258563) 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, 14356 + ... + 14373.

It is a Proth number, since it is equal to 505 ⋅ 2⁹ + 1 and 505 < 2⁹.

2²⁵⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

258561 is a deficient number, since it is larger than the sum of its proper divisors (114929).

258561 is a wasteful number, since it uses less digits than its factorization.

258561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28735 (or 28732 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 258561 is about 508.4889379328. The cubic root of 258561 is about 63.7070760647.

The spelling of 258561 in words is "two hundred fifty-eight thousand, five hundred sixty-one".