21112212211 has 4 divisors (see below), whose sum is σ = 21120949512. Its totient is φ = 21103474912.

The previous prime is 21112212169. The next prime is 21112212223. The reversal of 21112212211 is 11221221112.

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

It is a cyclic number.

It is not a de Polignac number, because 21112212211 - 2¹⁵ = 21112179443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112212271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4365025 + ... + 4369858.

It is an arithmetic number, because the mean of its divisors is an integer number (5280237378).

Almost surely, 2^21112212211 is an apocalyptic number.

21112212211 is a deficient number, since it is larger than the sum of its proper divisors (8737301).

21112212211 is an equidigital number, since it uses as much as digits as its factorization.

21112212211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8737300.

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

Adding to 21112212211 its reverse (11221221112), we get a palindrome (32333433323).

The spelling of 21112212211 in words is "twenty-one billion, one hundred twelve million, two hundred twelve thousand, two hundred eleven".