21222121111 has 8 divisors (see below), whose sum is σ = 21673062000. Its totient is φ = 20775902400.

The previous prime is 21222121097. The next prime is 21222121121. The reversal of 21222121111 is 11112122212.

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

It is a cyclic number.

It is not a de Polignac number, because 21222121111 - 2²¹ = 21220023959 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 (21222121121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1171461 + ... + 1189438.

It is an arithmetic number, because the mean of its divisors is an integer number (2709132750).

Almost surely, 2^21222121111 is an apocalyptic number.

21222121111 is a deficient number, since it is larger than the sum of its proper divisors (450940889).

21222121111 is a wasteful number, since it uses less digits than its factorization.

21222121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2361089.

The product of its digits is 32, while the sum is 16.

Adding to 21222121111 its reverse (11112122212), we get a palindrome (32334243323).

It can be divided in two parts, 2122212 and 1111, that multiplied together give a palindrome (2357777532).

The spelling of 21222121111 in words is "twenty-one billion, two hundred twenty-two million, one hundred twenty-one thousand, one hundred eleven".