821206 has 8 divisors (see below), whose sum is σ = 1243440. Its totient is φ = 406728.

The previous prime is 821173. The next prime is 821207. The reversal of 821206 is 602128.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (821207) 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, 1666 + ... + 2101.

It is an arithmetic number, because the mean of its divisors is an integer number (155430).

2⁸²¹²⁰⁶ is an apocalyptic number.

821206 is a deficient number, since it is larger than the sum of its proper divisors (422234).

821206 is a wasteful number, since it uses less digits than its factorization.

821206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3878.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 821206 is about 906.2041712550. The cubic root of 821206 is about 93.6448801013.

The spelling of 821206 in words is "eight hundred twenty-one thousand, two hundred six".