21221122211 has 8 divisors (see below), whose sum is σ = 22487946000. Its totient is φ = 19969290720.

The previous prime is 21221122187. The next prime is 21221122213. The reversal of 21221122211 is 11222112212.

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 21221122211 - 2⁶ = 21221122147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221122211.

It is not an unprimeable number, because it can be changed into a prime (21221122213) 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, 3745160 + ... + 3750821.

It is an arithmetic number, because the mean of its divisors is an integer number (2810993250).

Almost surely, 2^21221122211 is an apocalyptic number.

21221122211 is a deficient number, since it is larger than the sum of its proper divisors (1266823789).

21221122211 is a wasteful number, since it uses less digits than its factorization.

21221122211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7496149.

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

Adding to 21221122211 its reverse (11222112212), we get a palindrome (32443234423).

Subtracting from 21221122211 its reverse (11222112212), we obtain a palindrome (9999009999).

The spelling of 21221122211 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred eleven".