21081112 has 32 divisors (see below), whose sum is σ = 43278480. Its totient is φ = 9567360.

The previous prime is 21081101. The next prime is 21081119. The reversal of 21081112 is 21118012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21081119) 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, 4683 + ... + 8005.

Almost surely, 2^21081112 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 21081112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21639240).

21081112 is an abundant number, since it is smaller than the sum of its proper divisors (22197368).

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

21081112 is a wasteful number, since it uses less digits than its factorization.

21081112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3403 (or 3399 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

The square root of 21081112 is about 4591.4172104046. The cubic root of 21081112 is about 276.2471705859.

Adding to 21081112 its reverse (21118012), we get a palindrome (42199124).

The spelling of 21081112 in words is "twenty-one million, eighty-one thousand, one hundred twelve".