258721 has 2 divisors, whose sum is σ = 258722. Its totient is φ = 258720.

The previous prime is 258707. The next prime is 258733. The reversal of 258721 is 127852.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 239121 + 19600 = 489^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 258721 - 2¹⁷ = 127649 is a prime.

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

It is not a weakly prime, because it can be changed into another prime (258421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129360 + 129361.

It is an arithmetic number, because the mean of its divisors is an integer number (129361).

2²⁵⁸⁷²¹ is an apocalyptic number.

It is an amenable number.

258721 is a deficient number, since it is larger than the sum of its proper divisors (1).

258721 is an equidigital number, since it uses as much as digits as its factorization.

258721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1120, while the sum is 25.

The square root of 258721 is about 508.6462424908. The cubic root of 258721 is about 63.7202142028.

It can be divided in two parts, 258 and 721, that added together give a palindrome (979).

The spelling of 258721 in words is "two hundred fifty-eight thousand, seven hundred twenty-one".