82212221 has 32 divisors (see below), whose sum is σ = 112815360. Its totient is φ = 57977856.

The previous prime is 82212203. The next prime is 82212223. The reversal of 82212221 is 12221228.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 82212221 - 2¹⁴ = 82195837 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 82212193 and 82212202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82212223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27995 + ... + 30791.

It is an arithmetic number, because the mean of its divisors is an integer number (3525480).

Almost surely, 2^82212221 is an apocalyptic number.

It is an amenable number.

82212221 is a deficient number, since it is larger than the sum of its proper divisors (30603139).

82212221 is a wasteful number, since it uses less digits than its factorization.

82212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2853.

The product of its digits is 256, while the sum is 20.

The square root of 82212221 is about 9067.0955106914. The cubic root of 82212221 is about 434.8226184785.

Adding to 82212221 its reverse (12221228), we get a palindrome (94433449).

The spelling of 82212221 in words is "eighty-two million, two hundred twelve thousand, two hundred twenty-one".