251865222568121 has 2 divisors, whose sum is σ = 251865222568122. Its totient is φ = 251865222568120.

The previous prime is 251865222568051. The next prime is 251865222568153. The reversal of 251865222568121 is 121865222568152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 249285858086521 + 2579364481600 = 15788789^2 + 1606040^2 .

It is a cyclic number.

It is not a de Polignac number, because 251865222568121 - 2³⁴ = 251848042698937 is a prime.

It is not a weakly prime, because it can be changed into another prime (251865222567121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125932611284060 + 125932611284061.

It is an arithmetic number, because the mean of its divisors is an integer number (125932611284061).

Almost surely, 2^{251865222568121} is an apocalyptic number.

It is an amenable number.

251865222568121 is a deficient number, since it is larger than the sum of its proper divisors (1).

251865222568121 is an equidigital number, since it uses as much as digits as its factorization.

251865222568121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9216000, while the sum is 56.

The spelling of 251865222568121 in words is "two hundred fifty-one trillion, eight hundred sixty-five billion, two hundred twenty-two million, five hundred sixty-eight thousand, one hundred twenty-one".