28086727778 has 4 divisors (see below), whose sum is σ = 42130091670. Its totient is φ = 14043363888.

The previous prime is 28086727729. The next prime is 28086727847. The reversal of 28086727778 is 87772768082.

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

It can be written as a sum of positive squares in only one way, i.e., 24695179609 + 3391548169 = 157147^2 + 58237^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28086727778.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7021681943 + ... + 7021681946.

Almost surely, 2^28086727778 is an apocalyptic number.

28086727778 is a deficient number, since it is larger than the sum of its proper divisors (14043363892).

28086727778 is a wasteful number, since it uses less digits than its factorization.

28086727778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14043363891.

The product of its (nonzero) digits is 29503488, while the sum is 62.

The spelling of 28086727778 in words is "twenty-eight billion, eighty-six million, seven hundred twenty-seven thousand, seven hundred seventy-eight".