21222711 has 12 divisors (see below), whose sum is σ = 30695392. Its totient is φ = 14129856.

The previous prime is 21222697. The next prime is 21222739. The reversal of 21222711 is 11722212.

It is a happy number.

It is not a de Polignac number, because 21222711 - 2⁵ = 21222679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11055 + ... + 12831.

Almost surely, 2^21222711 is an apocalyptic number.

21222711 is a deficient number, since it is larger than the sum of its proper divisors (9472681).

21222711 is a wasteful number, since it uses less digits than its factorization.

21222711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3110 (or 3107 counting only the distinct ones).

The product of its digits is 112, while the sum is 18.

The square root of 21222711 is about 4606.8113701344. The cubic root of 21222711 is about 276.8642959818.

Adding to 21222711 its reverse (11722212), we get a palindrome (32944923).

The spelling of 21222711 in words is "twenty-one million, two hundred twenty-two thousand, seven hundred eleven".