128488987 has 4 divisors (see below), whose sum is σ = 140169816. Its totient is φ = 116808160.

The previous prime is 128488981. The next prime is 128488991. The reversal of 128488987 is 789884821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128488987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128488981) 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, 5840398 + ... + 5840419.

It is an arithmetic number, because the mean of its divisors is an integer number (35042454).

Almost surely, 2^128488987 is an apocalyptic number.

128488987 is a deficient number, since it is larger than the sum of its proper divisors (11680829).

128488987 is a wasteful number, since it uses less digits than its factorization.

128488987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11680828.

The product of its digits is 2064384, while the sum is 55.

The square root of 128488987 is about 11335.2982757403. The cubic root of 128488987 is about 504.6093596979.

The spelling of 128488987 in words is "one hundred twenty-eight million, four hundred eighty-eight thousand, nine hundred eighty-seven".