16003221 has 8 divisors (see below), whose sum is σ = 22979040. Its totient is φ = 9848112.

The previous prime is 16003217. The next prime is 16003237. The reversal of 16003221 is 12230061.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16003221 - 2² = 16003217 is a prime.

It is a super-2 number, since 2×16003221² = 512206164749682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16003221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16003021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 205131 + ... + 205208.

It is an arithmetic number, because the mean of its divisors is an integer number (2872380).

Almost surely, 2^16003221 is an apocalyptic number.

It is an amenable number.

16003221 is a deficient number, since it is larger than the sum of its proper divisors (6975819).

16003221 is a wasteful number, since it uses less digits than its factorization.

16003221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410355.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 16003221 is about 4000.4026047387. The cubic root of 16003221 is about 252.0011180348.

Adding to 16003221 its reverse (12230061), we get a palindrome (28233282).

The spelling of 16003221 in words is "sixteen million, three thousand, two hundred twenty-one".