21381112 has 8 divisors (see below), whose sum is σ = 40089600. Its totient is φ = 10690552.

The previous prime is 21381109. The next prime is 21381133. The reversal of 21381112 is 21118312.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 21381112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1336312 + ... + 1336327.

It is an arithmetic number, because the mean of its divisors is an integer number (5011200).

Almost surely, 2^21381112 is an apocalyptic number.

It is an amenable number.

21381112 is a deficient number, since it is larger than the sum of its proper divisors (18708488).

21381112 is a wasteful number, since it uses less digits than its factorization.

21381112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2672645 (or 2672641 counting only the distinct ones).

The product of its digits is 96, while the sum is 19.

The square root of 21381112 is about 4623.9714531991. The cubic root of 21381112 is about 277.5514045940.

Adding to 21381112 its reverse (21118312), we get a palindrome (42499424).

The spelling of 21381112 in words is "twenty-one million, three hundred eighty-one thousand, one hundred twelve".