51520551557 has 2 divisors, whose sum is σ = 51520551558. Its totient is φ = 51520551556.

The previous prime is 51520551491. The next prime is 51520551583. The reversal of 51520551557 is 75515502515.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39089639521 + 12430912036 = 197711^2 + 111494^2 .

It is a cyclic number.

It is not a de Polignac number, because 51520551557 - 2²⁴ = 51503774341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51520551857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25760275778 + 25760275779.

It is an arithmetic number, because the mean of its divisors is an integer number (25760275779).

Almost surely, 2^51520551557 is an apocalyptic number.

It is an amenable number.

51520551557 is a deficient number, since it is larger than the sum of its proper divisors (1).

51520551557 is an equidigital number, since it uses as much as digits as its factorization.

51520551557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 218750, while the sum is 41.

The spelling of 51520551557 in words is "fifty-one billion, five hundred twenty million, five hundred fifty-one thousand, five hundred fifty-seven".