21227212 has 12 divisors (see below), whose sum is σ = 37565640. Its totient is φ = 10494176.

The previous prime is 21227209. The next prime is 21227243. The reversal of 21227212 is 21272212.

It is a self number, because there is not a number n which added to its sum of digits gives 21227212.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 29458 + ... + 30169.

It is an arithmetic number, because the mean of its divisors is an integer number (3130470).

Almost surely, 2^21227212 is an apocalyptic number.

It is an amenable number.

21227212 is a deficient number, since it is larger than the sum of its proper divisors (16338428).

21227212 is a wasteful number, since it uses less digits than its factorization.

21227212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59720 (or 59718 counting only the distinct ones).

The product of its digits is 224, while the sum is 19.

The square root of 21227212 is about 4607.2998600048. The cubic root of 21227212 is about 276.8838674385.

Adding to 21227212 its reverse (21272212), we get a palindrome (42499424).

The spelling of 21227212 in words is "twenty-one million, two hundred twenty-seven thousand, two hundred twelve".