13128987 has 8 divisors (see below), whose sum is σ = 17579520. Its totient is φ = 8715560.

The previous prime is 13128971. The next prime is 13128991. The reversal of 13128987 is 78982131.

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 13128987 - 2⁴ = 13128971 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13128917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8439 + ... + 9872.

It is an arithmetic number, because the mean of its divisors is an integer number (2197440).

Almost surely, 2^13128987 is an apocalyptic number.

13128987 is a deficient number, since it is larger than the sum of its proper divisors (4450533).

13128987 is a wasteful number, since it uses less digits than its factorization.

13128987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18553.

The product of its digits is 24192, while the sum is 39.

The square root of 13128987 is about 3623.3944030425. The cubic root of 13128987 is about 235.9085816084.

The spelling of 13128987 in words is "thirteen million, one hundred twenty-eight thousand, nine hundred eighty-seven".