16004221 has 4 divisors (see below), whose sum is σ = 16027200. Its totient is φ = 15981244.

The previous prime is 16004207. The next prime is 16004273. The reversal of 16004221 is 12240061.

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 a cyclic number.

It is not a de Polignac number, because 16004221 - 2⁵ = 16004189 is a prime.

It is a super-2 number, since 2×16004221² = 512270179633682, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16004195 and 16004204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16004291) 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, 10411 + ... + 11848.

It is an arithmetic number, because the mean of its divisors is an integer number (4006800).

Almost surely, 2^16004221 is an apocalyptic number.

It is an amenable number.

16004221 is a deficient number, since it is larger than the sum of its proper divisors (22979).

16004221 is an equidigital number, since it uses as much as digits as its factorization.

16004221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22978.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 16004221 is about 4000.5275902061. The cubic root of 16004221 is about 252.0063668921.

Adding to 16004221 its reverse (12240061), we get a palindrome (28244282).

The spelling of 16004221 in words is "sixteen million, four thousand, two hundred twenty-one".