128144987 has 4 divisors (see below), whose sum is σ = 134889480. Its totient is φ = 121400496.

The previous prime is 128144981. The next prime is 128144999. The reversal of 128144987 is 789441821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789441821 = 7 ⋅112777403.

It is a cyclic number.

It is not a de Polignac number, because 128144987 - 2¹⁰ = 128143963 is a prime.

It is a super-2 number, since 2×128144987² = 32842275386460338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128144981) 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, 3372218 + ... + 3372255.

It is an arithmetic number, because the mean of its divisors is an integer number (33722370).

Almost surely, 2^128144987 is an apocalyptic number.

128144987 is a deficient number, since it is larger than the sum of its proper divisors (6744493).

128144987 is an equidigital number, since it uses as much as digits as its factorization.

128144987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6744492.

The product of its digits is 129024, while the sum is 44.

The square root of 128144987 is about 11320.1142662077. The cubic root of 128144987 is about 504.1586316715.

The spelling of 128144987 in words is "one hundred twenty-eight million, one hundred forty-four thousand, nine hundred eighty-seven".