987815 has 8 divisors (see below), whose sum is σ = 1223808. Its totient is φ = 764640.

The previous prime is 987809. The next prime is 987821. The reversal of 987815 is 518789.

It is an interprime number because it is at equal distance from previous prime (987809) and next prime (987821).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 987815 - 2⁸ = 987559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 3032 + ... + 3341.

It is an arithmetic number, because the mean of its divisors is an integer number (152976).

2⁹⁸⁷⁸¹⁵ is an apocalyptic number.

987815 is a deficient number, since it is larger than the sum of its proper divisors (235993).

987815 is a wasteful number, since it uses less digits than its factorization.

987815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6409.

The product of its digits is 20160, while the sum is 38.

The square root of 987815 is about 993.8888267809. Note that the first 4 decimals coincide. The cubic root of 987815 is about 99.5921723605.

The spelling of 987815 in words is "nine hundred eighty-seven thousand, eight hundred fifteen".