258181991 has 2 divisors, whose sum is σ = 258181992. Its totient is φ = 258181990.

The previous prime is 258181949. The next prime is 258181993. The reversal of 258181991 is 199181852.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 258181991 - 2⁶ = 258181927 is a prime.

It is a Sophie Germain prime.

Together with 258181993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (258181993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129090995 + 129090996.

It is an arithmetic number, because the mean of its divisors is an integer number (129090996).

Almost surely, 2^258181991 is an apocalyptic number.

258181991 is a deficient number, since it is larger than the sum of its proper divisors (1).

258181991 is an equidigital number, since it uses as much as digits as its factorization.

258181991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 44.

The square root of 258181991 is about 16068.0425379073. The cubic root of 258181991 is about 636.7593272053.

The spelling of 258181991 in words is "two hundred fifty-eight million, one hundred eighty-one thousand, nine hundred ninety-one".