128005489 has 4 divisors (see below), whose sum is σ = 134742640. Its totient is φ = 121268340.

The previous prime is 128005483. The next prime is 128005499. The reversal of 128005489 is 984500821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128005489 - 2⁵ = 128005457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128005483) 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, 3368547 + ... + 3368584.

It is an arithmetic number, because the mean of its divisors is an integer number (33685660).

Almost surely, 2^128005489 is an apocalyptic number.

128005489 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

128005489 is a deficient number, since it is larger than the sum of its proper divisors (6737151).

128005489 is an equidigital number, since it uses as much as digits as its factorization.

128005489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6737150.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 128005489 is about 11313.9510782043. The cubic root of 128005489 is about 503.9756237161.

The spelling of 128005489 in words is "one hundred twenty-eight million, five thousand, four hundred eighty-nine".