251240393 has 2 divisors, whose sum is σ = 251240394. Its totient is φ = 251240392.

The previous prime is 251240389. The next prime is 251240447. The reversal of 251240393 is 393042152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159693769 + 91546624 = 12637^2 + 9568^2 .

It is a cyclic number.

It is not a de Polignac number, because 251240393 - 2² = 251240389 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (251240383) 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 as a sum of consecutive naturals, namely, 125620196 + 125620197.

It is an arithmetic number, because the mean of its divisors is an integer number (125620197).

Almost surely, 2^251240393 is an apocalyptic number.

It is an amenable number.

251240393 is a deficient number, since it is larger than the sum of its proper divisors (1).

251240393 is an equidigital number, since it uses as much as digits as its factorization.

251240393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 251240393 is about 15850.5644378994. The cubic root of 251240393 is about 631.0006714195. Note that the first 3 decimals are identical.

The spelling of 251240393 in words is "two hundred fifty-one million, two hundred forty thousand, three hundred ninety-three".