21056112 has 200 divisors, whose sum is σ = 76340352. Its totient is φ = 5443200.

The previous prime is 21056089. The next prime is 21056129. The reversal of 21056112 is 21165012.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 99687 + ... + 99897.

Almost surely, 2^21056112 is an apocalyptic number.

21056112 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 21056112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38170176).

21056112 is an abundant number, since it is smaller than the sum of its proper divisors (55284240).

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

21056112 is a wasteful number, since it uses less digits than its factorization.

21056112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 21056112 is about 4588.6939318285. The cubic root of 21056112 is about 276.1379272805.

Subtracting 21056112 from its reverse (21165012), we obtain a square (108900 = 330²).

The spelling of 21056112 in words is "twenty-one million, fifty-six thousand, one hundred twelve".