21222586 has 24 divisors (see below), whose sum is σ = 40399776. Its totient is φ = 8268120.

The previous prime is 21222559. The next prime is 21222587. The reversal of 21222586 is 68522212.

It is not an unprimeable number, because it can be changed into a prime (21222587) 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 11 ways as a sum of consecutive naturals, for example, 8766 + ... + 10921.

It is an arithmetic number, because the mean of its divisors is an integer number (1683324).

Almost surely, 2^21222586 is an apocalyptic number.

21222586 is a deficient number, since it is larger than the sum of its proper divisors (19177190).

21222586 is a wasteful number, since it uses less digits than its factorization.

21222586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19714 (or 19707 counting only the distinct ones).

The product of its digits is 3840, while the sum is 28.

The square root of 21222586 is about 4606.7978032468. The cubic root of 21222586 is about 276.8637524115.

Adding to 21222586 its reverse (68522212), we get a palindrome (89744798).

The spelling of 21222586 in words is "twenty-one million, two hundred twenty-two thousand, five hundred eighty-six".