20990028320 has 48 divisors (see below), whose sum is σ = 51298916760. Its totient is φ = 8106491904.

The previous prime is 20990028317. The next prime is 20990028337. The reversal of 20990028320 is 2382009902.

It can be written as a sum of positive squares in 4 ways, for example, as 15118177936 + 5871850384 = 122956^2 + 76628^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2257217 + ... + 2266496.

Almost surely, 2^20990028320 is an apocalyptic number.

20990028320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20990028320 is an abundant number, since it is smaller than the sum of its proper divisors (30308888440).

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

20990028320 is a wasteful number, since it uses less digits than its factorization.

20990028320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4523757 (or 4523749 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 35.

The spelling of 20990028320 in words is "twenty billion, nine hundred ninety million, twenty-eight thousand, three hundred twenty".