20009033728 has 56 divisors (see below), whose sum is σ = 42369780132. Its totient is φ = 9415950336.

The previous prime is 20009033713. The next prime is 20009033729. The reversal of 20009033728 is 82733090002.

It can be written as a sum of positive squares in 2 ways, for example, as 14989594624 + 5019439104 = 122432^2 + 70848^2 .

It is a super-2 number, since 2×20009033728² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 20009033693 and 20009033702.

It is not an unprimeable number, because it can be changed into a prime (20009033729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67426 + ... + 211102.

Almost surely, 2^20009033728 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 20009033728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21184890066).

20009033728 is an abundant number, since it is smaller than the sum of its proper divisors (22360746404).

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

20009033728 is an equidigital number, since it uses as much as digits as its factorization.

20009033728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143720 (or 143696 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 34.

The spelling of 20009033728 in words is "twenty billion, nine million, thirty-three thousand, seven hundred twenty-eight".