20745721472 has 64 divisors (see below), whose sum is σ = 47369616000. Its totient is φ = 8865414144.

The previous prime is 20745721441. The next prime is 20745721481. The reversal of 20745721472 is 27412754702.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279533 + ... + 345875.

It is an arithmetic number, because the mean of its divisors is an integer number (740150250).

Almost surely, 2^20745721472 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 20745721472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23684808000).

20745721472 is an abundant number, since it is smaller than the sum of its proper divisors (26623894528).

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

20745721472 is an equidigital number, since it uses as much as digits as its factorization.

20745721472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66713 (or 66701 counting only the distinct ones).

The product of its (nonzero) digits is 219520, while the sum is 41.

The spelling of 20745721472 in words is "twenty billion, seven hundred forty-five million, seven hundred twenty-one thousand, four hundred seventy-two".