128975989 has 8 divisors (see below), whose sum is σ = 129837312. Its totient is φ = 128118000.

The previous prime is 128975893. The next prime is 128975999. The reversal of 128975989 is 989579821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128975989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128975999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171364 + ... + 172114.

It is an arithmetic number, because the mean of its divisors is an integer number (16229664).

Almost surely, 2^128975989 is an apocalyptic number.

It is an amenable number.

128975989 is a deficient number, since it is larger than the sum of its proper divisors (861323).

128975989 is an equidigital number, since it uses as much as digits as its factorization.

128975989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667.

The product of its digits is 3265920, while the sum is 58.

The square root of 128975989 is about 11356.7596170739. The cubic root of 128975989 is about 505.2460833790.

The spelling of 128975989 in words is "one hundred twenty-eight million, nine hundred seventy-five thousand, nine hundred eighty-nine".