28107876643866 has 48 divisors (see below), whose sum is σ = 60982383145320. Its totient is φ = 9356681886720.

The previous prime is 28107876643783. The next prime is 28107876643867. The reversal of 28107876643866 is 66834667870182.

It is a happy number.

28107876643866 is a `hidden beast` number, since 2 + 8 + 1 + 0 + 78 + 7 + 66 + 438 + 66 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 27304585693641 + 803290950225 = 5225379^2 + 896265^2 .

It is a super-3 number, since 3×28107876643866³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28107876643794 and 28107876643803.

It is not an unprimeable number, because it can be changed into a prime (28107876643867) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 138543436 + ... + 138746168.

Almost surely, 2^{28107876643866} is an apocalyptic number.

28107876643866 is an abundant number, since it is smaller than the sum of its proper divisors (32874506501454).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28107876643866 is a wasteful number, since it uses less digits than its factorization.

28107876643866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213071 (or 213068 counting only the distinct ones).

The product of its (nonzero) digits is 780337152, while the sum is 72.

The spelling of 28107876643866 in words is "twenty-eight trillion, one hundred seven billion, eight hundred seventy-six million, six hundred forty-three thousand, eight hundred sixty-six".