21211101111 has 8 divisors (see below), whose sum is σ = 29045832304. Its totient is φ = 13758552000.

The previous prime is 21211101097. The next prime is 21211101137. The reversal of 21211101111 is 11110111212.

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

It is not a de Polignac number, because 21211101111 - 2¹⁰ = 21211100087 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 (21211101181) 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, 95545390 + ... + 95545611.

It is an arithmetic number, because the mean of its divisors is an integer number (3630729038).

Almost surely, 2^21211101111 is an apocalyptic number.

21211101111 is a deficient number, since it is larger than the sum of its proper divisors (7834731193).

21211101111 is a wasteful number, since it uses less digits than its factorization.

21211101111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191091041.

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

Adding to 21211101111 its reverse (11110111212), we get a palindrome (32321212323).

It can be divided in two parts, 21211101 and 111, that added together give a palindrome (21211212).

The spelling of 21211101111 in words is "twenty-one billion, two hundred eleven million, one hundred one thousand, one hundred eleven".