817216 has 21 divisors (see below), whose sum is σ = 1636141. Its totient is φ = 404992.

The previous prime is 817211. The next prime is 817237. The reversal of 817216 is 612718.

The square root of 817216 is 904.

It is a perfect power (a square), and thus also a powerful number.

817216 is nontrivially palindromic in base 15.

It can be written as a sum of positive squares in only one way, i.e., 14400 + 802816 = 120^2 + 896^2 .

It is a Duffinian number.

It is a zygodrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (817211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7176 + ... + 7288.

817216 is a Friedman number, since it can be written as (8*(16*7+1))^2, using all its digits and the basic arithmetic operations.

2⁸¹⁷²¹⁶ is an apocalyptic number.

817216 is the 904-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 817216

817216 is an abundant number, since it is smaller than the sum of its proper divisors (818925).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

817216 is an equidigital number, since it uses as much as digits as its factorization.

817216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238 (or 115 counting only the distinct ones).

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

The cubic root of 817216 is about 93.4929694352.

Multiplying 817216 by its sum of digits (25), we get a square (20430400 = 4520²).

The spelling of 817216 in words is "eight hundred seventeen thousand, two hundred sixteen".