21943584640 has 64 divisors (see below), whose sum is σ = 52668267120. Its totient is φ = 8742400000.

The previous prime is 21943584601. The next prime is 21943584667. The reversal of 21943584640 is 4648534912.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 92340 + ... + 228940.

Almost surely, 2^21943584640 is an apocalyptic number.

21943584640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21943584640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26334133560).

21943584640 is an abundant number, since it is smaller than the sum of its proper divisors (30724682480).

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

21943584640 is a wasteful number, since it uses less digits than its factorization.

21943584640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136871 (or 136859 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 46.

The spelling of 21943584640 in words is "twenty-one billion, nine hundred forty-three million, five hundred eighty-four thousand, six hundred forty".