21222546 has 16 divisors (see below), whose sum is σ = 42613344. Its totient is φ = 7046144.

The previous prime is 21222529. The next prime is 21222557. The reversal of 21222546 is 64522212.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

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, 5340 + ... + 8423.

It is an arithmetic number, because the mean of its divisors is an integer number (2663334).

Almost surely, 2^21222546 is an apocalyptic number.

21222546 is an abundant number, since it is smaller than the sum of its proper divisors (21390798).

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

21222546 is a wasteful number, since it uses less digits than its factorization.

21222546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14025.

The product of its digits is 1920, while the sum is 24.

The square root of 21222546 is about 4606.7934618344. The cubic root of 21222546 is about 276.8635784685.

Adding to 21222546 its reverse (64522212), we get a palindrome (85744758).

The spelling of 21222546 in words is "twenty-one million, two hundred twenty-two thousand, five hundred forty-six".