21222672 has 20 divisors (see below), whose sum is σ = 54825360. Its totient is φ = 7074208.

The previous prime is 21222671. The next prime is 21222679. The reversal of 21222672 is 27622212.

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

It is not an unprimeable number, because it can be changed into a prime (21222671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 221022 + ... + 221117.

It is an arithmetic number, because the mean of its divisors is an integer number (2741268).

Almost surely, 2^21222672 is an apocalyptic number.

It is an amenable number.

21222672 is an abundant number, since it is smaller than the sum of its proper divisors (33602688).

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

21222672 is a wasteful number, since it uses less digits than its factorization.

21222672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442150 (or 442144 counting only the distinct ones).

The product of its digits is 1344, while the sum is 24.

The square root of 21222672 is about 4606.8071372698. The cubic root of 21222672 is about 276.8641263881.

Adding to 21222672 its reverse (27622212), we get a palindrome (48844884).

The spelling of 21222672 in words is "twenty-one million, two hundred twenty-two thousand, six hundred seventy-two".