33031221 has 16 divisors (see below), whose sum is σ = 47075904. Its totient is φ = 20528384.

The previous prime is 33031217. The next prime is 33031237. The reversal of 33031221 is 12213033.

It is not a de Polignac number, because 33031221 - 2² = 33031217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 33031221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33031211) 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 15 ways as a sum of consecutive naturals, for example, 2431 + ... + 8483.

It is an arithmetic number, because the mean of its divisors is an integer number (2942244).

Almost surely, 2^33031221 is an apocalyptic number.

It is an amenable number.

33031221 is a deficient number, since it is larger than the sum of its proper divisors (14044683).

33031221 is a wasteful number, since it uses less digits than its factorization.

33031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6180.

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 33031221 is about 5747.2794433540. The cubic root of 33031221 is about 320.8545550851.

Adding to 33031221 its reverse (12213033), we get a palindrome (45244254).

The spelling of 33031221 in words is "thirty-three million, thirty-one thousand, two hundred twenty-one".