823121 has 4 divisors (see below), whose sum is σ = 886452. Its totient is φ = 759792.

The previous prime is 823117. The next prime is 823127. The reversal of 823121 is 121328.

823121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 83521 + 739600 = 289^2 + 860^2 .

It is a cyclic number.

It is not a de Polignac number, because 823121 - 2² = 823117 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 823121.

It is not an unprimeable number, because it can be changed into a prime (823127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31646 + ... + 31671.

It is an arithmetic number, because the mean of its divisors is an integer number (221613).

2⁸²³¹²¹ is an apocalyptic number.

It is an amenable number.

823121 is a deficient number, since it is larger than the sum of its proper divisors (63331).

823121 is a wasteful number, since it uses less digits than its factorization.

823121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63330.

The product of its digits is 96, while the sum is 17.

The square root of 823121 is about 907.2601611445. The cubic root of 823121 is about 93.7176148882.

Adding to 823121 its reverse (121328), we get a palindrome (944449).

The spelling of 823121 in words is "eight hundred twenty-three thousand, one hundred twenty-one".