51657772943681 has 2 divisors, whose sum is σ = 51657772943682. Its totient is φ = 51657772943680.

The previous prime is 51657772943677. The next prime is 51657772943807. The reversal of 51657772943681 is 18634927775615.

51657772943681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33300112890625 + 18357660053056 = 5770625^2 + 4284584^2 .

It is a cyclic number.

It is not a de Polignac number, because 51657772943681 - 2² = 51657772943677 is a prime.

It is a super-2 number, since 2×51657772943681² (a number of 28 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (51657772942681) 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, 25828886471840 + 25828886471841.

It is an arithmetic number, because the mean of its divisors is an integer number (25828886471841).

Almost surely, 2^{51657772943681} is an apocalyptic number.

It is an amenable number.

51657772943681 is a deficient number, since it is larger than the sum of its proper divisors (1).

51657772943681 is an equidigital number, since it uses as much as digits as its factorization.

51657772943681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 533433600, while the sum is 71.

The spelling of 51657772943681 in words is "fifty-one trillion, six hundred fifty-seven billion, seven hundred seventy-two million, nine hundred forty-three thousand, six hundred eighty-one".