51784208681 has 2 divisors, whose sum is σ = 51784208682. Its totient is φ = 51784208680.

The previous prime is 51784208653. The next prime is 51784208683. The reversal of 51784208681 is 18680248715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48217133056 + 3567075625 = 219584^2 + 59725^2 .

It is a cyclic number.

It is not a de Polignac number, because 51784208681 - 2⁶ = 51784208617 is a prime.

It is a super-2 number, since 2×51784208681² (a number of 22 digits) contains 22 as substring.

Together with 51784208683, 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 (51784208683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25892104340 + 25892104341.

It is an arithmetic number, because the mean of its divisors is an integer number (25892104341).

Almost surely, 2^51784208681 is an apocalyptic number.

It is an amenable number.

51784208681 is a deficient number, since it is larger than the sum of its proper divisors (1).

51784208681 is an equidigital number, since it uses as much as digits as its factorization.

51784208681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 860160, while the sum is 50.

The spelling of 51784208681 in words is "fifty-one billion, seven hundred eighty-four million, two hundred eight thousand, six hundred eighty-one".