16221239 has 2 divisors, whose sum is σ = 16221240. Its totient is φ = 16221238.

The previous prime is 16221223. The next prime is 16221241. The reversal of 16221239 is 93212261.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16221239 - 2⁴ = 16221223 is a prime.

Together with 16221241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16223239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8110619 + 8110620.

It is an arithmetic number, because the mean of its divisors is an integer number (8110620).

Almost surely, 2^16221239 is an apocalyptic number.

16221239 is a deficient number, since it is larger than the sum of its proper divisors (1).

16221239 is an equidigital number, since it uses as much as digits as its factorization.

16221239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 16221239 is about 4027.5599312735. The cubic root of 16221239 is about 253.1403294887.

The spelling of 16221239 in words is "sixteen million, two hundred twenty-one thousand, two hundred thirty-nine".