21532808 has 16 divisors (see below), whose sum is σ = 44044560. Its totient is φ = 9787600.

The previous prime is 21532801. The next prime is 21532811. The reversal of 21532808 is 80823512.

It is not an unprimeable number, because it can be changed into a prime (21532801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122258 + ... + 122433.

It is an arithmetic number, because the mean of its divisors is an integer number (2752785).

Almost surely, 2^21532808 is an apocalyptic number.

It is an amenable number.

21532808 is an abundant number, since it is smaller than the sum of its proper divisors (22511752).

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

21532808 is a wasteful number, since it uses less digits than its factorization.

21532808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244708 (or 244704 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 21532808 is about 4640.3456767788. The cubic root of 21532808 is about 278.2062544731.

The spelling of 21532808 in words is "twenty-one million, five hundred thirty-two thousand, eight hundred eight".