20894480728 has 72 divisors (see below), whose sum is σ = 45162193140. Its totient is φ = 8986528800.

The previous prime is 20894480723. The next prime is 20894480741. The reversal of 20894480728 is 82708449802.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20894480723) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 25763443 + ... + 25764253.

Almost surely, 2^20894480728 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 20894480728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22581096570).

20894480728 is an abundant number, since it is smaller than the sum of its proper divisors (24267712412).

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

20894480728 is an equidigital number, since it uses as much as digits as its factorization.

20894480728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1677 (or 843 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 52.

The spelling of 20894480728 in words is "twenty billion, eight hundred ninety-four million, four hundred eighty thousand, seven hundred twenty-eight".