51808588217 has 2 divisors, whose sum is σ = 51808588218. Its totient is φ = 51808588216.

The previous prime is 51808588213. The next prime is 51808588253. The reversal of 51808588217 is 71288580815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50767299856 + 1041288361 = 225316^2 + 32269^2 .

It is a cyclic number.

It is not a de Polignac number, because 51808588217 - 2² = 51808588213 is a prime.

It is not a weakly prime, because it can be changed into another prime (51808588213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25904294108 + 25904294109.

It is an arithmetic number, because the mean of its divisors is an integer number (25904294109).

Almost surely, 2^51808588217 is an apocalyptic number.

It is an amenable number.

51808588217 is a deficient number, since it is larger than the sum of its proper divisors (1).

51808588217 is an equidigital number, since it uses as much as digits as its factorization.

51808588217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1433600, while the sum is 53.

The spelling of 51808588217 in words is "fifty-one billion, eight hundred eight million, five hundred eighty-eight thousand, two hundred seventeen".