21222111111 has 8 divisors (see below), whose sum is σ = 28296950784. Its totient is φ = 14147672760.

The previous prime is 21222111077. The next prime is 21222111137. The reversal of 21222111111 is 11111122212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21222111111 - 2¹⁵ = 21222078343 is a prime.

21222111111 is a modest number, since divided by 111111 gives 21222 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222118111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59380 + ... + 214406.

It is an arithmetic number, because the mean of its divisors is an integer number (3537118848).

Almost surely, 2^21222111111 is an apocalyptic number.

21222111111 is a deficient number, since it is larger than the sum of its proper divisors (7074839673).

21222111111 is a wasteful number, since it uses less digits than its factorization.

21222111111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200661.

The product of its digits is 16, while the sum is 15.

Adding to 21222111111 its reverse (11111122212), we get a palindrome (32333233323).

The spelling of 21222111111 in words is "twenty-one billion, two hundred twenty-two million, one hundred eleven thousand, one hundred eleven".