43212221 has 4 divisors (see below), whose sum is σ = 46536252. Its totient is φ = 39888192.

The previous prime is 43212199. The next prime is 43212229. The reversal of 43212221 is 12221234.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23088025 + 20124196 = 4805^2 + 4486^2 .

It is a cyclic number.

It is not a de Polignac number, because 43212221 - 2⁶ = 43212157 is a prime.

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 43212221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43212229) 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, 1661996 + ... + 1662021.

It is an arithmetic number, because the mean of its divisors is an integer number (11634063).

Almost surely, 2^43212221 is an apocalyptic number.

It is an amenable number.

43212221 is a deficient number, since it is larger than the sum of its proper divisors (3324031).

43212221 is a wasteful number, since it uses less digits than its factorization.

43212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3324030.

The product of its digits is 192, while the sum is 17.

The square root of 43212221 is about 6573.6003072898. The cubic root of 43212221 is about 350.9152128926.

Adding to 43212221 its reverse (12221234), we get a palindrome (55433455).

The spelling of 43212221 in words is "forty-three million, two hundred twelve thousand, two hundred twenty-one".