987591 has 8 divisors (see below), whose sum is σ = 1436544. Its totient is φ = 598520.

The previous prime is 987587. The next prime is 987593. The reversal of 987591 is 195789.

It is a happy number.

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 987591 - 2² = 987587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987593) 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, 14931 + ... + 14996.

It is an arithmetic number, because the mean of its divisors is an integer number (179568).

2⁹⁸⁷⁵⁹¹ is an apocalyptic number.

987591 is a deficient number, since it is larger than the sum of its proper divisors (448953).

987591 is a wasteful number, since it uses less digits than its factorization.

987591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29941.

The product of its digits is 22680, while the sum is 39.

The square root of 987591 is about 993.7761317319. The cubic root of 987591 is about 99.5846438479.

The spelling of 987591 in words is "nine hundred eighty-seven thousand, five hundred ninety-one".