28078128917 has 16 divisors (see below), whose sum is σ = 28789442880. Its totient is φ = 27375967872.

The previous prime is 28078128907. The next prime is 28078128937. The reversal of 28078128917 is 71982187082.

It is a cyclic number.

It is not a de Polignac number, because 28078128917 - 2¹⁰ = 28078127893 is a prime.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28078128907) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10463858 + ... + 10466540.

It is an arithmetic number, because the mean of its divisors is an integer number (1799340180).

Almost surely, 2^28078128917 is an apocalyptic number.

It is an amenable number.

28078128917 is a deficient number, since it is larger than the sum of its proper divisors (711313963).

28078128917 is a wasteful number, since it uses less digits than its factorization.

28078128917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4292.

The product of its (nonzero) digits is 903168, while the sum is 53.

The spelling of 28078128917 in words is "twenty-eight billion, seventy-eight million, one hundred twenty-eight thousand, nine hundred seventeen".