28766638779 has 8 divisors (see below), whose sum is σ = 38356402512. Its totient is φ = 19177317120.

The previous prime is 28766638709. The next prime is 28766638811. The reversal of 28766638779 is 97783666782.

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

It is not a de Polignac number, because 28766638779 - 2³³ = 20176704187 is a prime.

It is a super-2 number, since 2×28766638779² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28766638709) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96967 + ... + 258719.

It is an arithmetic number, because the mean of its divisors is an integer number (4794550314).

Almost surely, 2^28766638779 is an apocalyptic number.

28766638779 is a deficient number, since it is larger than the sum of its proper divisors (9589763733).

28766638779 is a wasteful number, since it uses less digits than its factorization.

28766638779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221037.

The product of its digits is 256048128, while the sum is 69.

The spelling of 28766638779 in words is "twenty-eight billion, seven hundred sixty-six million, six hundred thirty-eight thousand, seven hundred seventy-nine".