251953591 has 2 divisors, whose sum is σ = 251953592. Its totient is φ = 251953590.

The previous prime is 251953589. The next prime is 251953601. The reversal of 251953591 is 195359152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251953591 - 2¹ = 251953589 is a prime.

It is a super-2 number, since 2×251953591² = 126961224035590562, which contains 22 as substring.

Together with 251953589, 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 (251957591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125976795 + 125976796.

It is an arithmetic number, because the mean of its divisors is an integer number (125976796).

Almost surely, 2^251953591 is an apocalyptic number.

251953591 is the 8485-th centered heptagonal number.

251953591 is a deficient number, since it is larger than the sum of its proper divisors (1).

251953591 is an equidigital number, since it uses as much as digits as its factorization.

251953591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60750, while the sum is 40.

The square root of 251953591 is about 15873.0460529792. The cubic root of 251953591 is about 631.5971827909.

The spelling of 251953591 in words is "two hundred fifty-one million, nine hundred fifty-three thousand, five hundred ninety-one".