21233688 has 64 divisors (see below), whose sum is σ = 61340160. Its totient is φ = 5999616.

The previous prime is 21233651. The next prime is 21233689. The reversal of 21233688 is 88633212.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15645 + ... + 16947.

It is an arithmetic number, because the mean of its divisors is an integer number (958440).

Almost surely, 2^21233688 is an apocalyptic number.

21233688 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 21233688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30670080).

21233688 is an abundant number, since it is smaller than the sum of its proper divisors (40106472).

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

21233688 is a wasteful number, since it uses less digits than its factorization.

21233688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416 (or 1412 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21233688 is about 4608.0026041659. The cubic root of 21233688 is about 276.9120218284.

The spelling of 21233688 in words is "twenty-one million, two hundred thirty-three thousand, six hundred eighty-eight".