251798117 has 2 divisors, whose sum is σ = 251798118. Its totient is φ = 251798116.

The previous prime is 251798093. The next prime is 251798119. The reversal of 251798117 is 711897152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223771681 + 28026436 = 14959^2 + 5294^2 .

It is a cyclic number.

It is not a de Polignac number, because 251798117 - 2¹⁰ = 251797093 is a prime.

Together with 251798119, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251798119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125899058 + 125899059.

It is an arithmetic number, because the mean of its divisors is an integer number (125899059).

Almost surely, 2^251798117 is an apocalyptic number.

It is an amenable number.

251798117 is a deficient number, since it is larger than the sum of its proper divisors (1).

251798117 is an equidigital number, since it uses as much as digits as its factorization.

251798117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 41.

The square root of 251798117 is about 15868.1478755399. The cubic root of 251798117 is about 631.4672420014.

The spelling of 251798117 in words is "two hundred fifty-one million, seven hundred ninety-eight thousand, one hundred seventeen".