21452808 has 64 divisors (see below), whose sum is σ = 59774400. Its totient is φ = 6370560.

The previous prime is 21452801. The next prime is 21452831. The reversal of 21452808 is 80825412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21452801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7863 + ... + 10233.

It is an arithmetic number, because the mean of its divisors is an integer number (933975).

Almost surely, 2^21452808 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 21452808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29887200).

21452808 is an abundant number, since it is smaller than the sum of its proper divisors (38321592).

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

21452808 is a wasteful number, since it uses less digits than its factorization.

21452808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2422 (or 2418 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 21452808 is about 4631.7176079722. The cubic root of 21452808 is about 277.8612906348.

The spelling of 21452808 in words is "twenty-one million, four hundred fifty-two thousand, eight hundred eight".