16043221 has 4 divisors (see below), whose sum is σ = 16315200. Its totient is φ = 15771244.

The previous prime is 16043207. The next prime is 16043249. The reversal of 16043221 is 12234061.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12234061 = 7 ⋅1747723.

It is a cyclic number.

It is not a de Polignac number, because 16043221 - 2¹⁵ = 16010453 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 (16043281) 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, 135901 + ... + 136018.

It is an arithmetic number, because the mean of its divisors is an integer number (4078800).

Almost surely, 2^16043221 is an apocalyptic number.

It is an amenable number.

16043221 is a deficient number, since it is larger than the sum of its proper divisors (271979).

16043221 is an equidigital number, since it uses as much as digits as its factorization.

16043221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271978.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 16043221 is about 4005.3989813750. The cubic root of 16043221 is about 252.2109020114.

Adding to 16043221 its reverse (12234061), we get a palindrome (28277282).

The spelling of 16043221 in words is "sixteen million, forty-three thousand, two hundred twenty-one".