21113568 has 96 divisors (see below), whose sum is σ = 70398720. Its totient is φ = 6030720.

The previous prime is 21113549. The next prime is 21113581. The reversal of 21113568 is 86531112.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 4303 + ... + 7793.

It is an arithmetic number, because the mean of its divisors is an integer number (733320).

Almost surely, 2^21113568 is an apocalyptic number.

21113568 is a gapful number since it is divisible by the number (28) 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 21113568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35199360).

21113568 is an abundant number, since it is smaller than the sum of its proper divisors (49285152).

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

21113568 is a wasteful number, since it uses less digits than its factorization.

21113568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3517 (or 3503 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 21113568 is about 4594.9502717657. The cubic root of 21113568 is about 276.3888658449.

The spelling of 21113568 in words is "twenty-one million, one hundred thirteen thousand, five hundred sixty-eight".