128518389 has 6 divisors (see below), whose sum is σ = 185637686. Its totient is φ = 85678920.

The previous prime is 128518381. The next prime is 128518391. The reversal of 128518389 is 983815821.

It is a happy number.

128518389 is a `hidden beast` number, since 128 + 518 + 3 + 8 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 98903025 + 29615364 = 9945^2 + 5442^2 .

It is not a de Polignac number, because 128518389 - 2³ = 128518381 is a prime.

It is a super-2 number, since 2×128518389² = 33033952622310642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128518381) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7139902 + ... + 7139919.

Almost surely, 2^128518389 is an apocalyptic number.

It is an amenable number.

128518389 is a deficient number, since it is larger than the sum of its proper divisors (57119297).

128518389 is a wasteful number, since it uses less digits than its factorization.

128518389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14279827 (or 14279824 counting only the distinct ones).

The product of its digits is 138240, while the sum is 45.

The square root of 128518389 is about 11336.5951237574. The cubic root of 128518389 is about 504.6478465057.

The spelling of 128518389 in words is "one hundred twenty-eight million, five hundred eighteen thousand, three hundred eighty-nine".