21338688 has 56 divisors (see below), whose sum is σ = 64528192. Its totient is φ = 6096384.

The previous prime is 21338683. The next prime is 21338717. The reversal of 21338688 is 88683312.

It is a tau number, because it is divible by the number of its divisors (56).

It is a super-2 number, since 2×21338688² = 910679211122688, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21338683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6595 + ... + 9282.

Almost surely, 2^21338688 is an apocalyptic number.

21338688 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21338688 is an abundant number, since it is smaller than the sum of its proper divisors (43189504).

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

21338688 is a wasteful number, since it uses less digits than its factorization.

21338688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15899 (or 15889 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 21338688 is about 4619.3817768182. The cubic root of 21338688 is about 277.3677122897.

The spelling of 21338688 in words is "twenty-one million, three hundred thirty-eight thousand, six hundred eighty-eight".