16889221 has 2 divisors, whose sum is σ = 16889222. Its totient is φ = 16889220.

The previous prime is 16889189. The next prime is 16889251. The reversal of 16889221 is 12298861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11826721 + 5062500 = 3439^2 + 2250^2 .

It is a cyclic number.

It is not a de Polignac number, because 16889221 - 2⁵ = 16889189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16889251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8444610 + 8444611.

It is an arithmetic number, because the mean of its divisors is an integer number (8444611).

Almost surely, 2^16889221 is an apocalyptic number.

It is an amenable number.

16889221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16889221 is an equidigital number, since it uses as much as digits as its factorization.

16889221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 37.

The square root of 16889221 is about 4109.6497417663. The cubic root of 16889221 is about 256.5684238241.

The spelling of 16889221 in words is "sixteen million, eight hundred eighty-nine thousand, two hundred twenty-one".