43431221 has 4 divisors (see below), whose sum is σ = 44250732. Its totient is φ = 42611712.

The previous prime is 43431203. The next prime is 43431233. The reversal of 43431221 is 12213434.

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 36168196 + 7263025 = 6014^2 + 2695^2 .

It is a cyclic number.

It is not a de Polignac number, because 43431221 - 2¹⁴ = 43414837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 43431193 and 43431202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43431251) 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, 409676 + ... + 409781.

It is an arithmetic number, because the mean of its divisors is an integer number (11062683).

Almost surely, 2^43431221 is an apocalyptic number.

It is an amenable number.

43431221 is a deficient number, since it is larger than the sum of its proper divisors (819511).

43431221 is an equidigital number, since it uses as much as digits as its factorization.

43431221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 819510.

The product of its digits is 576, while the sum is 20.

The square root of 43431221 is about 6590.2367939248. The cubic root of 43431221 is about 351.5070282624.

Adding to 43431221 its reverse (12213434), we get a palindrome (55644655).

The spelling of 43431221 in words is "forty-three million, four hundred thirty-one thousand, two hundred twenty-one".