823221 has 24 divisors (see below), whose sum is σ = 1385280. Its totient is φ = 461376.

The previous prime is 823219. The next prime is 823231. The reversal of 823221 is 122328.

It is a happy number.

It is not a de Polignac number, because 823221 - 2¹ = 823219 is a prime.

It is a Curzon number.

823221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 823194 and 823203.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 823221.

It is not an unprimeable number, because it can be changed into a prime (823201) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4510 + ... + 4688.

It is an arithmetic number, because the mean of its divisors is an integer number (57720).

2⁸²³²²¹ is an apocalyptic number.

It is an amenable number.

823221 is a deficient number, since it is larger than the sum of its proper divisors (562059).

823221 is a wasteful number, since it uses less digits than its factorization.

823221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265 (or 262 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 823221 is about 907.3152704545. The cubic root of 823221 is about 93.7214099487.

Adding to 823221 its reverse (122328), we get a palindrome (945549).

The spelling of 823221 in words is "eight hundred twenty-three thousand, two hundred twenty-one".