822521 has 4 divisors (see below), whose sum is σ = 940032. Its totient is φ = 705012.

The previous prime is 822517. The next prime is 822539. The reversal of 822521 is 125228.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 822521 - 2² = 822517 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 822493 and 822502.

It is not an unprimeable number, because it can be changed into a prime (822541) by changing a digit.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58745 + ... + 58758.

It is an arithmetic number, because the mean of its divisors is an integer number (235008).

2⁸²²⁵²¹ is an apocalyptic number.

It is an amenable number.

822521 is a deficient number, since it is larger than the sum of its proper divisors (117511).

822521 is a wasteful number, since it uses less digits than its factorization.

822521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117510.

The product of its digits is 320, while the sum is 20.

The square root of 822521 is about 906.9294349617. The cubic root of 822521 is about 93.6948380679.

Adding to 822521 its reverse (125228), we get a palindrome (947749).

The spelling of 822521 in words is "eight hundred twenty-two thousand, five hundred twenty-one".