128171927 has 4 divisors (see below), whose sum is σ = 138031320. Its totient is φ = 118312536.

The previous prime is 128171917. The next prime is 128171933. The reversal of 128171927 is 729171821.

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

It is a cyclic number.

It is not a de Polignac number, because 128171927 - 2¹⁸ = 127909783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128171917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4929677 + ... + 4929702.

It is an arithmetic number, because the mean of its divisors is an integer number (34507830).

Almost surely, 2^128171927 is an apocalyptic number.

128171927 is a deficient number, since it is larger than the sum of its proper divisors (9859393).

128171927 is an equidigital number, since it uses as much as digits as its factorization.

128171927 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9859392.

The product of its digits is 14112, while the sum is 38.

The square root of 128171927 is about 11321.3041209924. The cubic root of 128171927 is about 504.1939590565.

The spelling of 128171927 in words is "one hundred twenty-eight million, one hundred seventy-one thousand, nine hundred twenty-seven".