21599960448 has 128 divisors (see below), whose sum is σ = 62674185600. Its totient is φ = 6536724480.

The previous prime is 21599960441. The next prime is 21599960449. The reversal of 21599960448 is 84406999512.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21599960441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3625440 + ... + 3631392.

It is an arithmetic number, because the mean of its divisors is an integer number (489642075).

Almost surely, 2^21599960448 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 21599960448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31337092800).

21599960448 is an abundant number, since it is smaller than the sum of its proper divisors (41074225152).

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

21599960448 is a wasteful number, since it uses less digits than its factorization.

21599960448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6840 (or 6828 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 57.

The spelling of 21599960448 in words is "twenty-one billion, five hundred ninety-nine million, nine hundred sixty thousand, four hundred forty-eight".