128381187 has 16 divisors (see below), whose sum is σ = 191081088. Its totient is φ = 75996480.

The previous prime is 128381177. The next prime is 128381191. The reversal of 128381187 is 781183821.

It is not a de Polignac number, because 128381187 - 2¹⁶ = 128315651 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128381117) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43818 + ... + 46655.

It is an arithmetic number, because the mean of its divisors is an integer number (11942568).

Almost surely, 2^128381187 is an apocalyptic number.

128381187 is a deficient number, since it is larger than the sum of its proper divisors (62699901).

128381187 is a wasteful number, since it uses less digits than its factorization.

128381187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90530.

The product of its digits is 21504, while the sum is 39.

The square root of 128381187 is about 11330.5422200352. The cubic root of 128381187 is about 504.4682007549.

The spelling of 128381187 in words is "one hundred twenty-eight million, three hundred eighty-one thousand, one hundred eighty-seven".