21101311112 has 64 divisors (see below), whose sum is σ = 46123499520. Its totient is φ = 8863864128.

The previous prime is 21101311103. The next prime is 21101311117. The reversal of 21101311112 is 21111310112.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is not an unprimeable number, because it can be changed into a prime (21101311117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 572423 + ... + 608169.

It is an arithmetic number, because the mean of its divisors is an integer number (720679680).

Almost surely, 2^21101311112 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 21101311112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23061749760).

21101311112 is an abundant number, since it is smaller than the sum of its proper divisors (25022188408).

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

21101311112 is a wasteful number, since it uses less digits than its factorization.

21101311112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35970 (or 35966 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 14.

Adding to 21101311112 its reverse (21111310112), we get a palindrome (42212621224).

The spelling of 21101311112 in words is "twenty-one billion, one hundred one million, three hundred eleven thousand, one hundred twelve".