51255803857 has 2 divisors, whose sum is σ = 51255803858. Its totient is φ = 51255803856.

The previous prime is 51255803849. The next prime is 51255803887. The reversal of 51255803857 is 75830855215.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32584221121 + 18671582736 = 180511^2 + 136644^2 .

It is a cyclic number.

It is not a de Polignac number, because 51255803857 - 2³ = 51255803849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 51255803857.

It is not a weakly prime, because it can be changed into another prime (51255803887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25627901928 + 25627901929.

It is an arithmetic number, because the mean of its divisors is an integer number (25627901929).

Almost surely, 2^51255803857 is an apocalyptic number.

It is an amenable number.

51255803857 is a deficient number, since it is larger than the sum of its proper divisors (1).

51255803857 is an equidigital number, since it uses as much as digits as its factorization.

51255803857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1680000, while the sum is 49.

The spelling of 51255803857 in words is "fifty-one billion, two hundred fifty-five million, eight hundred three thousand, eight hundred fifty-seven".