28385187787 has 4 divisors (see below), whose sum is σ = 30965659416. Its totient is φ = 25804716160.

The previous prime is 28385187757. The next prime is 28385187799. The reversal of 28385187787 is 78778158382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28385187787 - 2¹⁹ = 28384663499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28385187707) 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, 1290235798 + ... + 1290235819.

It is an arithmetic number, because the mean of its divisors is an integer number (7741414854).

Almost surely, 2^28385187787 is an apocalyptic number.

28385187787 is a deficient number, since it is larger than the sum of its proper divisors (2580471629).

28385187787 is a wasteful number, since it uses less digits than its factorization.

28385187787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2580471628.

The product of its digits is 42147840, while the sum is 64.

The spelling of 28385187787 in words is "twenty-eight billion, three hundred eighty-five million, one hundred eighty-seven thousand, seven hundred eighty-seven".