21095808 has 64 divisors (see below), whose sum is σ = 56585520. Its totient is φ = 6963200.

The previous prime is 21095783. The next prime is 21095839. The reversal of 21095808 is 80859012.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52408 + ... + 52808.

Almost surely, 2^21095808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21095808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28292760).

21095808 is an abundant number, since it is smaller than the sum of its proper divisors (35489712).

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

21095808 is a wasteful number, since it uses less digits than its factorization.

21095808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 21095808 is about 4593.0173089158. The cubic root of 21095808 is about 276.3113478680.

The spelling of 21095808 in words is "twenty-one million, ninety-five thousand, eight hundred eight".