21000044688064 has 168 divisors, whose sum is σ = 46246653453168. Its totient is φ = 9451432673280.

The previous prime is 21000044688013. The next prime is 21000044688071. The reversal of 21000044688064 is 46088644000012.

It is a self number, because there is not a number n which added to its sum of digits gives 21000044688064.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1040781144 + ... + 1040801320.

It is an arithmetic number, because the mean of its divisors is an integer number (275277699126).

Almost surely, 2^{21000044688064} 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 21000044688064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23123326726584).

21000044688064 is an abundant number, since it is smaller than the sum of its proper divisors (25246608765104).

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

21000044688064 is a wasteful number, since it uses less digits than its factorization.

21000044688064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22603 (or 22580 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 43.

Adding to 21000044688064 its reverse (46088644000012), we get a palindrome (67088688688076).

The spelling of 21000044688064 in words is "twenty-one trillion, forty-four million, six hundred eighty-eight thousand, sixty-four".