87509 has 2 divisors, whose sum is σ = 87510. Its totient is φ = 87508.

The previous prime is 87491. The next prime is 87511. The reversal of 87509 is 90578.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87025 + 484 = 295^2 + 22^2 .

It is a cyclic number.

It is not a de Polignac number, because 87509 - 2⁸ = 87253 is a prime.

Together with 87511, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43754 + 43755.

It is an arithmetic number, because the mean of its divisors is an integer number (43755).

2⁸⁷⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

87509 is a deficient number, since it is larger than the sum of its proper divisors (1).

87509 is an equidigital number, since it uses as much as digits as its factorization.

87509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 87509 is about 295.8192015404. The cubic root of 87509 is about 44.3967221561.

The spelling of 87509 in words is "eighty-seven thousand, five hundred nine".