251631120647 has 2 divisors, whose sum is σ = 251631120648. Its totient is φ = 251631120646.

The previous prime is 251631120623. The next prime is 251631120677. The reversal of 251631120647 is 746021136152.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 251631120647 - 2³⁶ = 182911643911 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 251631120647.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251631120677) 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, 125815560323 + 125815560324.

It is an arithmetic number, because the mean of its divisors is an integer number (125815560324).

Almost surely, 2^251631120647 is an apocalyptic number.

251631120647 is a deficient number, since it is larger than the sum of its proper divisors (1).

251631120647 is an equidigital number, since it uses as much as digits as its factorization.

251631120647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60480, while the sum is 38.

Adding to 251631120647 its reverse (746021136152), we get a palindrome (997652256799).

The spelling of 251631120647 in words is "two hundred fifty-one billion, six hundred thirty-one million, one hundred twenty thousand, six hundred forty-seven".