21101012112 has 160 divisors (see below), whose sum is σ = 57486070656. Its totient is φ = 6662656000.

The previous prime is 21101012111. The next prime is 21101012123. The reversal of 21101012112 is 21121010112.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21101012111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10533703 + ... + 10535705.

Almost surely, 2^21101012112 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 21101012112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28743035328).

21101012112 is an abundant number, since it is smaller than the sum of its proper divisors (36385058544).

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

21101012112 is a wasteful number, since it uses less digits than its factorization.

21101012112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2209 (or 2203 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21101012112 its reverse (21121010112), we get a palindrome (42222022224).

The spelling of 21101012112 in words is "twenty-one billion, one hundred one million, twelve thousand, one hundred twelve".