51566778839 has 2 divisors, whose sum is σ = 51566778840. Its totient is φ = 51566778838.

The previous prime is 51566778811. The next prime is 51566778853. The reversal of 51566778839 is 93887766515.

51566778839 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51566778839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51566778889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25783389419 + 25783389420.

It is an arithmetic number, because the mean of its divisors is an integer number (25783389420).

Almost surely, 2^51566778839 is an apocalyptic number.

51566778839 is a deficient number, since it is larger than the sum of its proper divisors (1).

51566778839 is an equidigital number, since it uses as much as digits as its factorization.

51566778839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 76204800, while the sum is 65.

The spelling of 51566778839 in words is "fifty-one billion, five hundred sixty-six million, seven hundred seventy-eight thousand, eight hundred thirty-nine".