20728472224 has 12 divisors (see below), whose sum is σ = 40809179754. Its totient is φ = 10364236096.

The previous prime is 20728472221. The next prime is 20728472231. The reversal of 20728472224 is 42227482702.

It can be written as a sum of positive squares in only one way, i.e., 14177188624 + 6551283600 = 119068^2 + 80940^2 .

It is a super-2 number, since 2×20728472224² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20728472221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323882347 + ... + 323882410.

Almost surely, 2^20728472224 is an apocalyptic number.

It is an amenable number.

20728472224 is a deficient number, since it is larger than the sum of its proper divisors (20080707530).

20728472224 is an equidigital number, since it uses as much as digits as its factorization.

20728472224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647764767 (or 647764759 counting only the distinct ones).

The product of its (nonzero) digits is 200704, while the sum is 40.

The spelling of 20728472224 in words is "twenty billion, seven hundred twenty-eight million, four hundred seventy-two thousand, two hundred twenty-four".