43121221 has 16 divisors (see below), whose sum is σ = 51020928. Its totient is φ = 35928000.

The previous prime is 43121209. The next prime is 43121227. The reversal of 43121221 is 12212134.

43121221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 43121221 - 2⁵ = 43121189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 43121195 and 43121204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43121227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20595 + ... + 22591.

It is an arithmetic number, because the mean of its divisors is an integer number (3188808).

Almost surely, 2^43121221 is an apocalyptic number.

It is an amenable number.

43121221 is a deficient number, since it is larger than the sum of its proper divisors (7899707).

43121221 is a wasteful number, since it uses less digits than its factorization.

43121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2172.

The product of its digits is 96, while the sum is 16.

The square root of 43121221 is about 6566.6750338356. The cubic root of 43121221 is about 350.6687106621.

Adding to 43121221 its reverse (12212134), we get a palindrome (55333355).

The spelling of 43121221 in words is "forty-three million, one hundred twenty-one thousand, two hundred twenty-one".