21221111222 has 4 divisors (see below), whose sum is σ = 31831666836. Its totient is φ = 10610555610.

The previous prime is 21221111173. The next prime is 21221111273. The reversal of 21221111222 is 22211112212.

21221111222 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21221111222² (a number of 21 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21221111222.

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, 5305277804 + ... + 5305277807.

It is an arithmetic number, because the mean of its divisors is an integer number (7957916709).

Almost surely, 2^21221111222 is an apocalyptic number.

21221111222 is a deficient number, since it is larger than the sum of its proper divisors (10610555614).

21221111222 is a wasteful number, since it uses less digits than its factorization.

21221111222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10610555613.

The product of its digits is 64, while the sum is 17.

Adding to 21221111222 its reverse (22211112212), we get a palindrome (43432223434).

The spelling of 21221111222 in words is "twenty-one billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twenty-two".