33213221 has 4 divisors (see below), whose sum is σ = 33229152. Its totient is φ = 33197292.

The previous prime is 33213217. The next prime is 33213227. The reversal of 33213221 is 12231233.

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 a cyclic number.

It is not a de Polignac number, because 33213221 - 2² = 33213217 is a prime.

It is a super-2 number, since 2×33213221² = 2206236098389682, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 33213221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33213227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4265 + ... + 9198.

It is an arithmetic number, because the mean of its divisors is an integer number (8307288).

It is a self-describing number.

Almost surely, 2^33213221 is an apocalyptic number.

It is an amenable number.

33213221 is a deficient number, since it is larger than the sum of its proper divisors (15931).

33213221 is a wasteful number, since it uses less digits than its factorization.

33213221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15930.

The product of its digits is 216, while the sum is 17.

The square root of 33213221 is about 5763.0912711842. The cubic root of 33213221 is about 321.4427723579.

Adding to 33213221 its reverse (12231233), we get a palindrome (45444454).

The spelling of 33213221 in words is "thirty-three million, two hundred thirteen thousand, two hundred twenty-one".