128185387 has 4 divisors (see below), whose sum is σ = 139838616. Its totient is φ = 116532160.

The previous prime is 128185373. The next prime is 128185397. The reversal of 128185387 is 783581821.

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 128185387 - 2¹¹ = 128183339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128185327) 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, 5826598 + ... + 5826619.

It is an arithmetic number, because the mean of its divisors is an integer number (34959654).

Almost surely, 2^128185387 is an apocalyptic number.

128185387 is a deficient number, since it is larger than the sum of its proper divisors (11653229).

128185387 is a wasteful number, since it uses less digits than its factorization.

128185387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11653228.

The product of its digits is 107520, while the sum is 43.

The square root of 128185387 is about 11321.8985598706. The cubic root of 128185387 is about 504.2116077812.

It can be divided in two parts, 1281 and 85387, that added together give a palindrome (86668).

The spelling of 128185387 in words is "one hundred twenty-eight million, one hundred eighty-five thousand, three hundred eighty-seven".