816217 has 2 divisors, whose sum is σ = 816218. Its totient is φ = 816216.

The previous prime is 816209. The next prime is 816223. The reversal of 816217 is 712618.

816217 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 can be written as a sum of positive squares in only one way, i.e., 767376 + 48841 = 876^2 + 221^2 .

It is a cyclic number.

It is not a de Polignac number, because 816217 - 2³ = 816209 is a prime.

816217 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 816191 and 816200.

It is not a weakly prime, because it can be changed into another prime (816227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408108 + 408109.

It is an arithmetic number, because the mean of its divisors is an integer number (408109).

2⁸¹⁶²¹⁷ is an apocalyptic number.

It is an amenable number.

816217 is a deficient number, since it is larger than the sum of its proper divisors (1).

816217 is an equidigital number, since it uses as much as digits as its factorization.

816217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 25.

The square root of 816217 is about 903.4472867855. The cubic root of 816217 is about 93.4548572915.

The spelling of 816217 in words is "eight hundred sixteen thousand, two hundred seventeen".