51116105659981 has 2 divisors, whose sum is σ = 51116105659982. Its totient is φ = 51116105659980.

The previous prime is 51116105659979. The next prime is 51116105659991. The reversal of 51116105659981 is 18995650161115.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48007354842756 + 3108750817225 = 6928734^2 + 1763165^2 .

It is a cyclic number.

It is not a de Polignac number, because 51116105659981 - 2¹ = 51116105659979 is a prime.

It is a super-2 number, since 2×51116105659981² (a number of 28 digits) contains 22 as substring.

Together with 51116105659979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51116105659961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25558052829990 + 25558052829991.

It is an arithmetic number, because the mean of its divisors is an integer number (25558052829991).

Almost surely, 2^{51116105659981} is an apocalyptic number.

It is an amenable number.

51116105659981 is a deficient number, since it is larger than the sum of its proper divisors (1).

51116105659981 is an equidigital number, since it uses as much as digits as its factorization.

51116105659981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916000, while the sum is 58.

The spelling of 51116105659981 in words is "fifty-one trillion, one hundred sixteen billion, one hundred five million, six hundred fifty-nine thousand, nine hundred eighty-one".