251261602129 has 2 divisors, whose sum is σ = 251261602130. Its totient is φ = 251261602128.

The previous prime is 251261602121. The next prime is 251261602159. The reversal of 251261602129 is 921206162152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 244651912129 + 6609690000 = 494623^2 + 81300^2 .

It is a cyclic number.

It is not a de Polignac number, because 251261602129 - 2³ = 251261602121 is a prime.

It is not a weakly prime, because it can be changed into another prime (251261602121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125630801064 + 125630801065.

It is an arithmetic number, because the mean of its divisors is an integer number (125630801065).

Almost surely, 2^251261602129 is an apocalyptic number.

It is an amenable number.

251261602129 is a deficient number, since it is larger than the sum of its proper divisors (1).

251261602129 is an equidigital number, since it uses as much as digits as its factorization.

251261602129 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 251261602129 in words is "two hundred fifty-one billion, two hundred sixty-one million, six hundred two thousand, one hundred twenty-nine".