43890221 has 4 divisors (see below), whose sum is σ = 44113212. Its totient is φ = 43667232.

The previous prime is 43890211. The next prime is 43890241. The reversal of 43890221 is 12209834.

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 43626025 + 264196 = 6605^2 + 514^2 .

It is a cyclic number.

It is not a de Polignac number, because 43890221 - 2⁶ = 43890157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43890211) 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, 111200 + ... + 111593.

It is an arithmetic number, because the mean of its divisors is an integer number (11028303).

Almost surely, 2^43890221 is an apocalyptic number.

It is an amenable number.

43890221 is a deficient number, since it is larger than the sum of its proper divisors (222991).

43890221 is a wasteful number, since it uses less digits than its factorization.

43890221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222990.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 43890221 is about 6624.9695093638. The cubic root of 43890221 is about 352.7409843859.

The spelling of 43890221 in words is "forty-three million, eight hundred ninety thousand, two hundred twenty-one".