21222272 has 16 divisors (see below), whose sum is σ = 42279000. Its totient is φ = 10611072.

The previous prime is 21222269. The next prime is 21222293. The reversal of 21222272 is 27222212.

It is a tau number, because it is divible by the number of its divisors (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82772 + ... + 83027.

Almost surely, 2^21222272 is an apocalyptic number.

It is an amenable number.

21222272 is a deficient number, since it is larger than the sum of its proper divisors (21056728).

21222272 is an equidigital number, since it uses as much as digits as its factorization.

21222272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165813 (or 165801 counting only the distinct ones).

The product of its digits is 448, while the sum is 20.

The square root of 21222272 is about 4606.7637230490. The cubic root of 21222272 is about 276.8623869535.

Adding to 21222272 its reverse (27222212), we get a palindrome (48444484).

The spelling of 21222272 in words is "twenty-one million, two hundred twenty-two thousand, two hundred seventy-two".