33121221 has 8 divisors (see below), whose sum is σ = 50470464. Its totient is φ = 18926400.

The previous prime is 33121213. The next prime is 33121247. The reversal of 33121221 is 12212133.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 33121221 - 2³ = 33121213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 33121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33121271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 788580 + ... + 788621.

It is an arithmetic number, because the mean of its divisors is an integer number (6308808).

Almost surely, 2^33121221 is an apocalyptic number.

It is an amenable number.

33121221 is a deficient number, since it is larger than the sum of its proper divisors (17349243).

33121221 is a wasteful number, since it uses less digits than its factorization.

33121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1577211.

The product of its digits is 72, while the sum is 15.

The square root of 33121221 is about 5755.1039087057. The cubic root of 33121221 is about 321.1457010755.

Adding to 33121221 its reverse (12212133), we get a palindrome (45333354).

The spelling of 33121221 in words is "thirty-three million, one hundred twenty-one thousand, two hundred twenty-one".