249958991 has 2 divisors, whose sum is σ = 249958992. Its totient is φ = 249958990.

The previous prime is 249958981. The next prime is 249958993. The reversal of 249958991 is 199859942.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-249958991 is a prime.

Together with 249958993, 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 (249958993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124979495 + 124979496.

It is an arithmetic number, because the mean of its divisors is an integer number (124979496).

Almost surely, 2^249958991 is an apocalyptic number.

249958991 is a deficient number, since it is larger than the sum of its proper divisors (1).

249958991 is an equidigital number, since it uses as much as digits as its factorization.

249958991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2099520, while the sum is 56.

The square root of 249958991 is about 15810.0914292106. The cubic root of 249958991 is about 629.9260776623.

The spelling of 249958991 in words is "two hundred forty-nine million, nine hundred fifty-eight thousand, nine hundred ninety-one".