28127823778 has 4 divisors (see below), whose sum is σ = 42191735670. Its totient is φ = 14063911888.

The previous prime is 28127823751. The next prime is 28127823781. The reversal of 28127823778 is 87732872182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87732872182 = 2 ⋅43866436091.

It can be written as a sum of positive squares in only one way, i.e., 21040372809 + 7087450969 = 145053^2 + 84187^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7031955943 + ... + 7031955946.

Almost surely, 2^28127823778 is an apocalyptic number.

28127823778 is a deficient number, since it is larger than the sum of its proper divisors (14063911892).

28127823778 is a wasteful number, since it uses less digits than its factorization.

28127823778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14063911891.

The product of its digits is 4214784, while the sum is 55.

The spelling of 28127823778 in words is "twenty-eight billion, one hundred twenty-seven million, eight hundred twenty-three thousand, seven hundred seventy-eight".