51391544317 has 2 divisors, whose sum is σ = 51391544318. Its totient is φ = 51391544316.

The previous prime is 51391544291. The next prime is 51391544353. The reversal of 51391544317 is 71344519315.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50501775076 + 889769241 = 224726^2 + 29829^2 .

It is a cyclic number.

It is not a de Polignac number, because 51391544317 - 2⁷ = 51391544189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51391544377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25695772158 + 25695772159.

It is an arithmetic number, because the mean of its divisors is an integer number (25695772159).

Almost surely, 2^51391544317 is an apocalyptic number.

It is an amenable number.

51391544317 is a deficient number, since it is larger than the sum of its proper divisors (1).

51391544317 is an equidigital number, since it uses as much as digits as its factorization.

51391544317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 226800, while the sum is 43.

The spelling of 51391544317 in words is "fifty-one billion, three hundred ninety-one million, five hundred forty-four thousand, three hundred seventeen".