87309 has 12 divisors (see below), whose sum is σ = 128700. Its totient is φ = 57024.

The previous prime is 87299. The next prime is 87313. The reversal of 87309 is 90378.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 38025 + 49284 = 195^2 + 222^2 .

It is not a de Polignac number, because 87309 - 2⁴ = 87293 is a prime.

It is a super-2 number, since 2×87309² = 15245722962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87359) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 747 + ... + 855.

It is an arithmetic number, because the mean of its divisors is an integer number (10725).

2⁸⁷³⁰⁹ is an apocalyptic number.

87309 is a gapful number since it is divisible by the number (89) formed by its first and last digit.

It is an amenable number.

87309 is a deficient number, since it is larger than the sum of its proper divisors (41391).

87309 is a wasteful number, since it uses less digits than its factorization.

87309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 87309 is about 295.4809638538. The cubic root of 87309 is about 44.3628737613.

The spelling of 87309 in words is "eighty-seven thousand, three hundred nine".