28128728228 has 6 divisors (see below), whose sum is σ = 49225274406. Its totient is φ = 14064364112.

The previous prime is 28128728227. The next prime is 28128728231. The reversal of 28128728228 is 82282782182.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21327097444 + 6801630784 = 146038^2 + 82472^2 .

It is not an unprimeable number, because it can be changed into a prime (28128728227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3516091025 + ... + 3516091032.

It is an arithmetic number, because the mean of its divisors is an integer number (8204212401).

Almost surely, 2^28128728228 is an apocalyptic number.

It is an amenable number.

28128728228 is a deficient number, since it is larger than the sum of its proper divisors (21096546178).

28128728228 is a wasteful number, since it uses less digits than its factorization.

28128728228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7032182061 (or 7032182059 counting only the distinct ones).

The product of its digits is 917504, while the sum is 50.

The spelling of 28128728228 in words is "twenty-eight billion, one hundred twenty-eight million, seven hundred twenty-eight thousand, two hundred twenty-eight".