43216221 has 4 divisors (see below), whose sum is σ = 57621632. Its totient is φ = 28810812.

The previous prime is 43216213. The next prime is 43216231. The reversal of 43216221 is 12261234.

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 not a de Polignac number, because 43216221 - 2³ = 43216213 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43216231) 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, 7202701 + ... + 7202706.

It is an arithmetic number, because the mean of its divisors is an integer number (14405408).

Almost surely, 2^43216221 is an apocalyptic number.

It is an amenable number.

43216221 is a deficient number, since it is larger than the sum of its proper divisors (14405411).

43216221 is a wasteful number, since it uses less digits than its factorization.

43216221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14405410.

The product of its digits is 576, while the sum is 21.

The square root of 43216221 is about 6573.9045475273. The cubic root of 43216221 is about 350.9260402119.

Adding to 43216221 its reverse (12261234), we get a palindrome (55477455).

It can be divided in two parts, 432 and 16221, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 43216221 in words is "forty-three million, two hundred sixteen thousand, two hundred twenty-one".