21320112 has 80 divisors (see below), whose sum is σ = 60710400. Its totient is φ = 6393600.

The previous prime is 21320107. The next prime is 21320183. The reversal of 21320112 is 21102312.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78537 + ... + 78807.

It is an arithmetic number, because the mean of its divisors is an integer number (758880).

Almost surely, 2^21320112 is an apocalyptic number.

21320112 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 21320112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30355200).

21320112 is an abundant number, since it is smaller than the sum of its proper divisors (39390288).

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

21320112 is a wasteful number, since it uses less digits than its factorization.

21320112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 436 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21320112 is about 4617.3706803764. The cubic root of 21320112 is about 277.2872031467.

Adding to 21320112 its reverse (21102312), we get a palindrome (42422424).

The spelling of 21320112 in words is "twenty-one million, three hundred twenty thousand, one hundred twelve".