8212221 has 6 divisors (see below), whose sum is σ = 11862110. Its totient is φ = 5474808.

The previous prime is 8212213. The next prime is 8212277. The reversal of 8212221 is 1222128.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 5616900 + 2595321 = 2370^2 + 1611^2 .

It is not a de Polignac number, because 8212221 - 2³ = 8212213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 8212194 and 8212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8212291) 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 5 ways as a sum of consecutive naturals, for example, 456226 + ... + 456243.

Almost surely, 2^8212221 is an apocalyptic number.

It is an amenable number.

8212221 is a deficient number, since it is larger than the sum of its proper divisors (3649889).

8212221 is a wasteful number, since it uses less digits than its factorization.

8212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 912475 (or 912472 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 8212221 is about 2865.6972973432. The cubic root of 8212221 is about 201.7530966943.

Adding to 8212221 its reverse (1222128), we get a palindrome (9434349).

The spelling of 8212221 in words is "eight million, two hundred twelve thousand, two hundred twenty-one".