21100112 has 40 divisors (see below), whose sum is σ = 45077472. Its totient is φ = 9488000.

The previous prime is 21100103. The next prime is 21100129.

21100112 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21100112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17183 + ... + 18369.

Almost surely, 2^21100112 is an apocalyptic number.

21100112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21100112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22538736).

21100112 is an abundant number, since it is smaller than the sum of its proper divisors (23977360).

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

21100112 is a wasteful number, since it uses less digits than its factorization.

21100112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307 (or 1301 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 21100112 is about 4593.4858223358. The cubic root of 21100112 is about 276.3301377491.

It can be divided in two parts, 21100 and 112, that added together give a palindrome (21212).

The spelling of 21100112 in words is "twenty-one million, one hundred thousand, one hundred twelve".