821212 has 24 divisors (see below), whose sum is σ = 1662080. Its totient is φ = 347760.

The previous prime is 821209. The next prime is 821263. The reversal of 821212 is 212128.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3787 + ... + 3997.

2⁸²¹²¹² is an apocalyptic number.

It is an amenable number.

821212 is an abundant number, since it is smaller than the sum of its proper divisors (840868).

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

821212 is a wasteful number, since it uses less digits than its factorization.

821212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361 (or 359 counting only the distinct ones).

The product of its digits is 64, while the sum is 16.

The square root of 821212 is about 906.2074817612. The cubic root of 821212 is about 93.6451081674.

The spelling of 821212 in words is "eight hundred twenty-one thousand, two hundred twelve".