251240420393 has 2 divisors, whose sum is σ = 251240420394. Its totient is φ = 251240420392.

The previous prime is 251240420383. The next prime is 251240420477. The reversal of 251240420393 is 393024042152.

251240420393 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 206399393344 + 44841027049 = 454312^2 + 211757^2 .

It is a cyclic number.

It is not a de Polignac number, because 251240420393 - 2⁴ = 251240420377 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 (251240420303) 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, 125620210196 + 125620210197.

It is an arithmetic number, because the mean of its divisors is an integer number (125620210197).

Almost surely, 2^251240420393 is an apocalyptic number.

It is an amenable number.

251240420393 is a deficient number, since it is larger than the sum of its proper divisors (1).

251240420393 is an equidigital number, since it uses as much as digits as its factorization.

251240420393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 35.

The spelling of 251240420393 in words is "two hundred fifty-one billion, two hundred forty million, four hundred twenty thousand, three hundred ninety-three".