21111111112 has 64 divisors (see below), whose sum is σ = 48999847680. Its totient is φ = 8303323392.

The previous prime is 21111111107. The next prime is 21111111143.

21111111112 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21111111092 and 21111111101.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 42133 + ... + 209755.

It is an arithmetic number, because the mean of its divisors is an integer number (765622620).

Almost surely, 2^21111111112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111111112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24499923840).

21111111112 is an abundant number, since it is smaller than the sum of its proper divisors (27888736568).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111111112 is a wasteful number, since it uses less digits than its factorization.

21111111112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167822 (or 167818 counting only the distinct ones).

The product of its digits is 4, while the sum is 13.

The spelling of 21111111112 in words is "twenty-one billion, one hundred eleven million, one hundred eleven thousand, one hundred twelve".