258668561 has 2 divisors, whose sum is σ = 258668562. Its totient is φ = 258668560.

The previous prime is 258668551. The next prime is 258668563. The reversal of 258668561 is 165866852.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 134212225 + 124456336 = 11585^2 + 11156^2 .

It is a cyclic number.

It is not a de Polignac number, because 258668561 - 2⁶ = 258668497 is a prime.

Together with 258668563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (258668563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129334280 + 129334281.

It is an arithmetic number, because the mean of its divisors is an integer number (129334281).

Almost surely, 2^258668561 is an apocalyptic number.

It is an amenable number.

258668561 is a deficient number, since it is larger than the sum of its proper divisors (1).

258668561 is an equidigital number, since it uses as much as digits as its factorization.

258668561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 691200, while the sum is 47.

The square root of 258668561 is about 16083.1763342942. The cubic root of 258668561 is about 637.1590885702.

The spelling of 258668561 in words is "two hundred fifty-eight million, six hundred sixty-eight thousand, five hundred sixty-one".