128767876805 has 4 divisors (see below), whose sum is σ = 154521452172. Its totient is φ = 103014301440.

The previous prime is 128767876801. The next prime is 128767876823. The reversal of 128767876805 is 508678767821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 508678767821 = 7 ⋅72668395403.

It can be written as a sum of positive squares in 2 ways, for example, as 42422405089 + 86345471716 = 205967^2 + 293846^2 .

It is not a de Polignac number, because 128767876805 - 2² = 128767876801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128767876801) 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, 12876787676 + ... + 12876787685.

It is an arithmetic number, because the mean of its divisors is an integer number (38630363043).

Almost surely, 2^128767876805 is an apocalyptic number.

It is an amenable number.

128767876805 is a deficient number, since it is larger than the sum of its proper divisors (25753575367).

128767876805 is an equidigital number, since it uses as much as digits as its factorization.

128767876805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25753575366.

The product of its (nonzero) digits is 63221760, while the sum is 65.

The spelling of 128767876805 in words is "one hundred twenty-eight billion, seven hundred sixty-seven million, eight hundred seventy-six thousand, eight hundred five".