128338491 has 16 divisors (see below), whose sum is σ = 181677600. Its totient is φ = 80306688.

The previous prime is 128338489. The next prime is 128338513. The reversal of 128338491 is 194833821.

It is not a de Polignac number, because 128338491 - 2¹ = 128338489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128338421) 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, 16605 + ... + 23073.

It is an arithmetic number, because the mean of its divisors is an integer number (11354850).

Almost surely, 2^128338491 is an apocalyptic number.

128338491 is a deficient number, since it is larger than the sum of its proper divisors (53339109).

128338491 is a wasteful number, since it uses less digits than its factorization.

128338491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6878.

The product of its digits is 41472, while the sum is 39.

The square root of 128338491 is about 11328.6579522907. The cubic root of 128338491 is about 504.4122705392.

The spelling of 128338491 in words is "one hundred twenty-eight million, three hundred thirty-eight thousand, four hundred ninety-one".