2186868720217 has 2 divisors, whose sum is σ = 2186868720218. Its totient is φ = 2186868720216.

The previous prime is 2186868720191. The next prime is 2186868720227. The reversal of 2186868720217 is 7120278686812.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1949944131216 + 236924589001 = 1396404^2 + 486749^2 .

It is a cyclic number.

It is not a de Polignac number, because 2186868720217 - 2¹⁹ = 2186868195929 is a prime.

It is not a weakly prime, because it can be changed into another prime (2186868720227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1093434360108 + 1093434360109.

It is an arithmetic number, because the mean of its divisors is an integer number (1093434360109).

Almost surely, 2^{2186868720217} is an apocalyptic number.

It is an amenable number.

2186868720217 is a deficient number, since it is larger than the sum of its proper divisors (1).

2186868720217 is an equidigital number, since it uses as much as digits as its factorization.

2186868720217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7225344, while the sum is 58.

The spelling of 2186868720217 in words is "two trillion, one hundred eighty-six billion, eight hundred sixty-eight million, seven hundred twenty thousand, two hundred seventeen".