816817 has 2 divisors, whose sum is σ = 816818. Its totient is φ = 816816.

The previous prime is 816811. The next prime is 816821. The reversal of 816817 is 718618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 703921 + 112896 = 839^2 + 336^2 .

It is a cyclic number.

It is not a de Polignac number, because 816817 - 2⁷ = 816689 is a prime.

It is a super-2 number, since 2×816817² = 1334380022978, which contains 22 as substring.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (816811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 408408 + 408409.

It is an arithmetic number, because the mean of its divisors is an integer number (408409).

2⁸¹⁶⁸¹⁷ is an apocalyptic number.

It is an amenable number.

816817 is a deficient number, since it is larger than the sum of its proper divisors (1).

816817 is an equidigital number, since it uses as much as digits as its factorization.

816817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 31.

The square root of 816817 is about 903.7792872156. The cubic root of 816817 is about 93.4777511953.

The spelling of 816817 in words is "eight hundred sixteen thousand, eight hundred seventeen".