3991587 has 4 divisors (see below), whose sum is σ = 5322120. Its totient is φ = 2661056.

The previous prime is 3991579. The next prime is 3991601. The reversal of 3991587 is 7851993.

It is a happy number.

3991587 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 3991587 - 2³ = 3991579 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (3991517) 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 3 ways as a sum of consecutive naturals, for example, 665262 + ... + 665267.

It is an arithmetic number, because the mean of its divisors is an integer number (1330530).

Almost surely, 2^3991587 is an apocalyptic number.

3991587 is a deficient number, since it is larger than the sum of its proper divisors (1330533).

3991587 is a wasteful number, since it uses less digits than its factorization.

3991587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1330532.

The product of its digits is 68040, while the sum is 42.

The square root of 3991587 is about 1997.8956429203. The cubic root of 3991587 is about 158.6287370398.

The spelling of 3991587 in words is "three million, nine hundred ninety-one thousand, five hundred eighty-seven".