128889599 has 4 divisors (see below), whose sum is σ = 133047360. Its totient is φ = 124731840.

The previous prime is 128889589. The next prime is 128889617. The reversal of 128889599 is 995988821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 995988821 = 1249 ⋅797429.

It is a cyclic number.

It is not a de Polignac number, because 128889599 - 2¹² = 128885503 is a prime.

It is a super-2 number, since 2×128889599² = 33225057460761602, 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 (128889589) 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, 2078834 + ... + 2078895.

It is an arithmetic number, because the mean of its divisors is an integer number (33261840).

Almost surely, 2^128889599 is an apocalyptic number.

128889599 is a deficient number, since it is larger than the sum of its proper divisors (4157761).

128889599 is an equidigital number, since it uses as much as digits as its factorization.

128889599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4157760.

The product of its digits is 3732480, while the sum is 59.

The square root of 128889599 is about 11352.9555182780. The cubic root of 128889599 is about 505.1332511159.

Subtracting from 128889599 its sum of digits (59), we obtain a triangular number (128889540 = T₁₆₀₅₅).

The spelling of 128889599 in words is "one hundred twenty-eight million, eight hundred eighty-nine thousand, five hundred ninety-nine".