21222189 has 16 divisors (see below), whose sum is σ = 31531840. Its totient is φ = 14106960.

The previous prime is 21222181. The next prime is 21222211. The reversal of 21222189 is 98122212.

It is not a de Polignac number, because 21222189 - 2³ = 21222181 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10434 + ... + 12300.

It is an arithmetic number, because the mean of its divisors is an integer number (1970740).

Almost surely, 2^21222189 is an apocalyptic number.

It is an amenable number.

21222189 is a deficient number, since it is larger than the sum of its proper divisors (10309651).

21222189 is a wasteful number, since it uses less digits than its factorization.

21222189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2297 (or 2291 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 21222189 is about 4606.7547145469. The cubic root of 21222189 is about 276.8620260181.

The spelling of 21222189 in words is "twenty-one million, two hundred twenty-two thousand, one hundred eighty-nine".