21380112 has 160 divisors (see below), whose sum is σ = 68328960. Its totient is φ = 6438528.

The previous prime is 21380081. The next prime is 21380113. The reversal of 21380112 is 21108312.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21380113) 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, 454873 + ... + 454919.

It is an arithmetic number, because the mean of its divisors is an integer number (427056).

Almost surely, 2^21380112 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 21380112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34164480).

21380112 is an abundant number, since it is smaller than the sum of its proper divisors (46948848).

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

21380112 is an equidigital number, since it uses as much as digits as its factorization.

21380112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 21380112 is about 4623.8633197793. The cubic root of 21380112 is about 277.5470774768.

Adding to 21380112 its reverse (21108312), we get a palindrome (42488424).

The spelling of 21380112 in words is "twenty-one million, three hundred eighty thousand, one hundred twelve".