21248812008 has 48 divisors (see below), whose sum is σ = 57556699200. Its totient is φ = 7081973280.

The previous prime is 21248812007. The next prime is 21248812021. The reversal of 21248812008 is 80021884212.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21248812003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 681643 + ... + 712133.

It is an arithmetic number, because the mean of its divisors is an integer number (1199097900).

Almost surely, 2^21248812008 is an apocalyptic number.

It is an amenable number.

21248812008 is an abundant number, since it is smaller than the sum of its proper divisors (36307887192).

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

21248812008 is a wasteful number, since it uses less digits than its factorization.

21248812008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40182 (or 40175 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 36.

The spelling of 21248812008 in words is "twenty-one billion, two hundred forty-eight million, eight hundred twelve thousand, eight".