21112308 has 72 divisors (see below), whose sum is σ = 61443200. Its totient is φ = 5987520.

The previous prime is 21112291. The next prime is 21112339. The reversal of 21112308 is 80321112.

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 pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49938 + ... + 50358.

Almost surely, 2^21112308 is an apocalyptic number.

21112308 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 21112308, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30721600).

21112308 is an abundant number, since it is smaller than the sum of its proper divisors (40330892).

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

21112308 is a wasteful number, since it uses less digits than its factorization.

21112308 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637 (or 632 counting only the distinct ones).

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

The square root of 21112308 is about 4594.8131626868. The cubic root of 21112308 is about 276.3833676917.

The spelling of 21112308 in words is "twenty-one million, one hundred twelve thousand, three hundred eight".