20204728128 has 280 divisors, whose sum is σ = 64910576808. Its totient is φ = 6177337344.

The previous prime is 20204728099. The next prime is 20204728129. The reversal of 20204728128 is 82182740202.

It can be written as a sum of positive squares in 4 ways, for example, as 3202654464 + 17002073664 = 56592^2 + 130392^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20204728092 and 20204728101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20204728129) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 11657950 + ... + 11659682.

Almost surely, 2^20204728128 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 20204728128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32455288404).

20204728128 is an abundant number, since it is smaller than the sum of its proper divisors (44705848680).

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

20204728128 is a wasteful number, since it uses less digits than its factorization.

20204728128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1943 (or 1924 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 36.

The spelling of 20204728128 in words is "twenty billion, two hundred four million, seven hundred twenty-eight thousand, one hundred twenty-eight".