16221439 has 16 divisors (see below), whose sum is σ = 18063360. Its totient is φ = 14473440.

The previous prime is 16221433. The next prime is 16221467. The reversal of 16221439 is 93412261.

It is a cyclic number.

It is not a de Polignac number, because 16221439 - 2³ = 16221431 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 (16221431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 84834 + ... + 85024.

It is an arithmetic number, because the mean of its divisors is an integer number (1128960).

Almost surely, 2^16221439 is an apocalyptic number.

16221439 is a deficient number, since it is larger than the sum of its proper divisors (1841921).

16221439 is a wasteful number, since it uses less digits than its factorization.

16221439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390.

The product of its digits is 2592, while the sum is 28.

The square root of 16221439 is about 4027.5847601261. The cubic root of 16221439 is about 253.1413698502.

The spelling of 16221439 in words is "sixteen million, two hundred twenty-one thousand, four hundred thirty-nine".