21424559208 has 128 divisors (see below), whose sum is σ = 58544640000. Its totient is φ = 6493923072.

The previous prime is 21424559161. The next prime is 21424559243. The reversal of 21424559208 is 80295542412.

It is a self number, because there is not a number n which added to its sum of digits gives 21424559208.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16242373 + ... + 16243691.

It is an arithmetic number, because the mean of its divisors is an integer number (457380000).

Almost surely, 2^21424559208 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 21424559208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29272320000).

21424559208 is an abundant number, since it is smaller than the sum of its proper divisors (37120080792).

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

21424559208 is a wasteful number, since it uses less digits than its factorization.

21424559208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2079 (or 2075 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 42.

The spelling of 21424559208 in words is "twenty-one billion, four hundred twenty-four million, five hundred fifty-nine thousand, two hundred eight".