21211110111 has 8 divisors (see below), whose sum is σ = 28703592064. Its totient is φ = 13929684120.

The previous prime is 21211110097. The next prime is 21211110113. The reversal of 21211110111 is 11101111212.

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

It is not a de Polignac number, because 21211110111 - 2⁵ = 21211110079 is a prime.

It is a super-2 number, since 2×21211110111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211110113) 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, 52763755 + ... + 52764156.

It is an arithmetic number, because the mean of its divisors is an integer number (3587949008).

Almost surely, 2^21211110111 is an apocalyptic number.

21211110111 is a deficient number, since it is larger than the sum of its proper divisors (7492481953).

21211110111 is a wasteful number, since it uses less digits than its factorization.

21211110111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105527981.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21211110111 its reverse (11101111212), we get a palindrome (32312221323).

It can be divided in two parts, 212111 and 10111, that added together give a palindrome (222222).

The spelling of 21211110111 in words is "twenty-one billion, two hundred eleven million, one hundred ten thousand, one hundred eleven".