16221311 has 2 divisors, whose sum is σ = 16221312. Its totient is φ = 16221310.

The previous prime is 16221253. The next prime is 16221313. The reversal of 16221311 is 11312261.

It is a strong prime.

It is an emirp because it is prime and its reverse (11312261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16221311 - 2¹⁰ = 16220287 is a prime.

Together with 16221313, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16221311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16221313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8110655 + 8110656.

It is an arithmetic number, because the mean of its divisors is an integer number (8110656).

Almost surely, 2^16221311 is an apocalyptic number.

16221311 is a deficient number, since it is larger than the sum of its proper divisors (1).

16221311 is an equidigital number, since it uses as much as digits as its factorization.

16221311 is an evil number, because the sum of its binary digits is even.

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

The square root of 16221311 is about 4027.5688696781. The cubic root of 16221311 is about 253.1407040199.

Adding to 16221311 its reverse (11312261), we get a palindrome (27533572).

The spelling of 16221311 in words is "sixteen million, two hundred twenty-one thousand, three hundred eleven".