51678463861 has 2 divisors, whose sum is σ = 51678463862. Its totient is φ = 51678463860.

The previous prime is 51678463847. The next prime is 51678463871. The reversal of 51678463861 is 16836487615.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33258816900 + 18419646961 = 182370^2 + 135719^2 .

It is a cyclic number.

It is not a de Polignac number, because 51678463861 - 2³³ = 43088529269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51678463871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25839231930 + 25839231931.

It is an arithmetic number, because the mean of its divisors is an integer number (25839231931).

Almost surely, 2^51678463861 is an apocalyptic number.

It is an amenable number.

51678463861 is a deficient number, since it is larger than the sum of its proper divisors (1).

51678463861 is an equidigital number, since it uses as much as digits as its factorization.

51678463861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5806080, while the sum is 55.

The spelling of 51678463861 in words is "fifty-one billion, six hundred seventy-eight million, four hundred sixty-three thousand, eight hundred sixty-one".