258918991 has 2 divisors, whose sum is σ = 258918992. Its totient is φ = 258918990.

The previous prime is 258918917. The next prime is 258918997. The reversal of 258918991 is 199819852.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 258918991 - 2²³ = 250530383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (258918997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129459495 + 129459496.

It is an arithmetic number, because the mean of its divisors is an integer number (129459496).

Almost surely, 2^258918991 is an apocalyptic number.

258918991 is a deficient number, since it is larger than the sum of its proper divisors (1).

258918991 is an equidigital number, since it uses as much as digits as its factorization.

258918991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 52.

The square root of 258918991 is about 16090.9599154308. The cubic root of 258918991 is about 637.3646441323.

The spelling of 258918991 in words is "two hundred fifty-eight million, nine hundred eighteen thousand, nine hundred ninety-one".