51217255757 has 2 divisors, whose sum is σ = 51217255758. Its totient is φ = 51217255756.

The previous prime is 51217255717. The next prime is 51217255769. The reversal of 51217255757 is 75755271215.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29374189321 + 21843066436 = 171389^2 + 147794^2 .

It is a cyclic number.

It is not a de Polignac number, because 51217255757 - 2⁶ = 51217255693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51217255717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25608627878 + 25608627879.

It is an arithmetic number, because the mean of its divisors is an integer number (25608627879).

Almost surely, 2^51217255757 is an apocalyptic number.

It is an amenable number.

51217255757 is a deficient number, since it is larger than the sum of its proper divisors (1).

51217255757 is an equidigital number, since it uses as much as digits as its factorization.

51217255757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 857500, while the sum is 47.

The spelling of 51217255757 in words is "fifty-one billion, two hundred seventeen million, two hundred fifty-five thousand, seven hundred fifty-seven".