251906931641 has 2 divisors, whose sum is σ = 251906931642. Its totient is φ = 251906931640.

The previous prime is 251906931511. The next prime is 251906931671. The reversal of 251906931641 is 146139609152.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179453904400 + 72453027241 = 423620^2 + 269171^2 .

It is a cyclic number.

It is not a de Polignac number, because 251906931641 - 2¹⁴ = 251906915257 is a prime.

It is not a weakly prime, because it can be changed into another prime (251906931671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125953465820 + 125953465821.

It is an arithmetic number, because the mean of its divisors is an integer number (125953465821).

Almost surely, 2^251906931641 is an apocalyptic number.

It is an amenable number.

251906931641 is a deficient number, since it is larger than the sum of its proper divisors (1).

251906931641 is an equidigital number, since it uses as much as digits as its factorization.

251906931641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 349920, while the sum is 47.

The spelling of 251906931641 in words is "two hundred fifty-one billion, nine hundred six million, nine hundred thirty-one thousand, six hundred forty-one".