21144443208 has 64 divisors (see below), whose sum is σ = 63592320000. Its totient is φ = 5723307072.

The previous prime is 21144443147. The next prime is 21144443231. The reversal of 21144443208 is 80234444112.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3308908 + ... + 3315291.

It is an arithmetic number, because the mean of its divisors is an integer number (993630000).

Almost surely, 2^21144443208 is an apocalyptic number.

21144443208 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21144443208 is an abundant number, since it is smaller than the sum of its proper divisors (42447876792).

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

21144443208 is a wasteful number, since it uses less digits than its factorization.

21144443208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6624234 (or 6624230 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 33.

The spelling of 21144443208 in words is "twenty-one billion, one hundred forty-four million, four hundred forty-three thousand, two hundred eight".