21222168 has 32 divisors (see below), whose sum is σ = 57879360. Its totient is φ = 6430880.

The previous prime is 21222163. The next prime is 21222181. The reversal of 21222168 is 86122212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39930 + ... + 40457.

It is an arithmetic number, because the mean of its divisors is an integer number (1808730).

Almost surely, 2^21222168 is an apocalyptic number.

It is an amenable number.

21222168 is an abundant number, since it is smaller than the sum of its proper divisors (36657192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21222168 is a wasteful number, since it uses less digits than its factorization.

21222168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80407 (or 80403 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 21222168 is about 4606.7524352845. The cubic root of 21222168 is about 276.8619346969.

The spelling of 21222168 in words is "twenty-one million, two hundred twenty-two thousand, one hundred sixty-eight".