28129395218 has 8 divisors (see below), whose sum is σ = 42990207948. Its totient is φ = 13799325904.

The previous prime is 28129395211. The next prime is 28129395221. The reversal of 28129395218 is 81259392182.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 25135882849 + 2993512369 = 158543^2 + 54713^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (28129395211) 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, 132685721 + ... + 132685932.

Almost surely, 2^28129395218 is an apocalyptic number.

28129395218 is a deficient number, since it is larger than the sum of its proper divisors (14860812730).

28129395218 is a wasteful number, since it uses less digits than its factorization.

28129395218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265371708.

The product of its digits is 622080, while the sum is 50.

The spelling of 28129395218 in words is "twenty-eight billion, one hundred twenty-nine million, three hundred ninety-five thousand, two hundred eighteen".