128784171 has 4 divisors (see below), whose sum is σ = 171712232. Its totient is φ = 85856112.

The previous prime is 128784169. The next prime is 128784193. The reversal of 128784171 is 171487821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 171487821 = 3 ⋅57162607.

It is not a de Polignac number, because 128784171 - 2¹ = 128784169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128784101) 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, 21464026 + ... + 21464031.

It is an arithmetic number, because the mean of its divisors is an integer number (42928058).

Almost surely, 2^128784171 is an apocalyptic number.

128784171 is a deficient number, since it is larger than the sum of its proper divisors (42928061).

128784171 is an equidigital number, since it uses as much as digits as its factorization.

128784171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42928060.

The product of its digits is 25088, while the sum is 39.

The square root of 128784171 is about 11348.3113721822. The cubic root of 128784171 is about 504.9954853696.

It can be divided in two parts, 1287 and 84171, that added together give a palindrome (85458).

The spelling of 128784171 in words is "one hundred twenty-eight million, seven hundred eighty-four thousand, one hundred seventy-one".