251230643 has 4 divisors (see below), whose sum is σ = 251281368. Its totient is φ = 251179920.

The previous prime is 251230631. The next prime is 251230663. The reversal of 251230643 is 346032152.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 251230643 - 2⁸ = 251230387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251230613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17018 + ... + 28143.

It is an arithmetic number, because the mean of its divisors is an integer number (62820342).

Almost surely, 2^251230643 is an apocalyptic number.

251230643 is a deficient number, since it is larger than the sum of its proper divisors (50725).

251230643 is an equidigital number, since it uses as much as digits as its factorization.

251230643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50724.

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 251230643 is about 15850.2568748901. The cubic root of 251230643 is about 630.9925088040.

Adding to 251230643 its reverse (346032152), we get a palindrome (597262795).

The spelling of 251230643 in words is "two hundred fifty-one million, two hundred thirty thousand, six hundred forty-three".