51353786681 has 2 divisors, whose sum is σ = 51353786682. Its totient is φ = 51353786680.

The previous prime is 51353786639. The next prime is 51353786683. The reversal of 51353786681 is 18668735315.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43033428025 + 8320358656 = 207445^2 + 91216^2 .

It is a cyclic number.

It is not a de Polignac number, because 51353786681 - 2¹⁴ = 51353770297 is a prime.

It is a super-2 number, since 2×51353786681² (a number of 22 digits) contains 22 as substring.

Together with 51353786683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (51353786683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25676893340 + 25676893341.

It is an arithmetic number, because the mean of its divisors is an integer number (25676893341).

Almost surely, 2^51353786681 is an apocalyptic number.

It is an amenable number.

51353786681 is a deficient number, since it is larger than the sum of its proper divisors (1).

51353786681 is an equidigital number, since it uses as much as digits as its factorization.

51353786681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3628800, while the sum is 53.

The spelling of 51353786681 in words is "fifty-one billion, three hundred fifty-three million, seven hundred eighty-six thousand, six hundred eighty-one".