20728913472 has 140 divisors (see below), whose sum is σ = 61840803420. Its totient is φ = 6865357824.

The previous prime is 20728913453. The next prime is 20728913477. The reversal of 20728913472 is 27431982702.

20728913472 is a `hidden beast` number, since 20 + 7 + 289 + 1 + 347 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 11309046336 + 9419867136 = 106344^2 + 97056^2 .

It is not an unprimeable number, because it can be changed into a prime (20728913477) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 801154 + ... + 826622.

Almost surely, 2^20728913472 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 20728913472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30920401710).

20728913472 is an abundant number, since it is smaller than the sum of its proper divisors (41111889948).

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

20728913472 is a wasteful number, since it uses less digits than its factorization.

20728913472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25650 (or 25631 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 20728913472 in words is "twenty billion, seven hundred twenty-eight million, nine hundred thirteen thousand, four hundred seventy-two".