16211321 has 4 divisors (see below), whose sum is σ = 18527232. Its totient is φ = 13895412.

The previous prime is 16211309. The next prime is 16211323. The reversal of 16211321 is 12311261.

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 16211321 - 2⁶ = 16211257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16211321.

It is not an unprimeable number, because it can be changed into a prime (16211323) 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 3 ways as a sum of consecutive naturals, for example, 1157945 + ... + 1157958.

It is an arithmetic number, because the mean of its divisors is an integer number (4631808).

Almost surely, 2^16211321 is an apocalyptic number.

It is an amenable number.

16211321 is a deficient number, since it is larger than the sum of its proper divisors (2315911).

16211321 is an equidigital number, since it uses as much as digits as its factorization.

16211321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2315910.

The product of its digits is 72, while the sum is 17.

The square root of 16211321 is about 4026.3284764162. The cubic root of 16211321 is about 253.0887272314.

Adding to 16211321 its reverse (12311261), we get a palindrome (28522582).

The spelling of 16211321 in words is "sixteen million, two hundred eleven thousand, three hundred twenty-one".