87005 has 4 divisors (see below), whose sum is σ = 104412. Its totient is φ = 69600.

The previous prime is 86993. The next prime is 87011. The reversal of 87005 is 50078.

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

It can be written as a sum of positive squares in 2 ways, for example, as 41209 + 45796 = 203^2 + 214^2 .

It is not a de Polignac number, because 87005 - 2¹⁴ = 70621 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 3 ways as a sum of consecutive naturals, for example, 8696 + ... + 8705.

It is an arithmetic number, because the mean of its divisors is an integer number (26103).

2⁸⁷⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

87005 is a deficient number, since it is larger than the sum of its proper divisors (17407).

87005 is a wasteful number, since it uses less digits than its factorization.

87005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17406.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 87005 is about 294.9660997471. The cubic root of 87005 is about 44.3113250604.

Adding to 87005 its sum of digits (20), we get a square (87025 = 295²).

The spelling of 87005 in words is "eighty-seven thousand, five".