128959987 has 8 divisors (see below), whose sum is σ = 139374704. Its totient is φ = 118615968.

The previous prime is 128959979. The next prime is 128959993. The reversal of 128959987 is 789959821.

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

It is a cyclic number.

It is not a de Polignac number, because 128959987 - 2³ = 128959979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128959997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13848 + ... + 21205.

It is an arithmetic number, because the mean of its divisors is an integer number (17421838).

Almost surely, 2^128959987 is an apocalyptic number.

128959987 is a deficient number, since it is larger than the sum of its proper divisors (10414717).

128959987 is a wasteful number, since it uses less digits than its factorization.

128959987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35349.

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

The square root of 128959987 is about 11356.0550808809. The cubic root of 128959987 is about 505.2251872875.

The spelling of 128959987 in words is "one hundred twenty-eight million, nine hundred fifty-nine thousand, nine hundred eighty-seven".