21648008 has 16 divisors (see below), whose sum is σ = 40642560. Its totient is φ = 10810000.

The previous prime is 21648001. The next prime is 21648047. The reversal of 21648008 is 80084612.

It is not an unprimeable number, because it can be changed into a prime (21648001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8033 + ... + 10383.

It is an arithmetic number, because the mean of its divisors is an integer number (2540160).

Almost surely, 2^21648008 is an apocalyptic number.

It is an amenable number.

21648008 is a deficient number, since it is larger than the sum of its proper divisors (18994552).

21648008 is a wasteful number, since it uses less digits than its factorization.

21648008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3508 (or 3504 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 21648008 is about 4652.7419872587. The cubic root of 21648008 is about 278.7015045640.

The spelling of 21648008 in words is "twenty-one million, six hundred forty-eight thousand, eight".