65909 has 4 divisors (see below), whose sum is σ = 69804. Its totient is φ = 62016.

The previous prime is 65899. The next prime is 65921. The reversal of 65909 is 90956.

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 34225 + 31684 = 185^2 + 178^2 .

It is not a de Polignac number, because 65909 - 2¹² = 61813 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11, base 13 and base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 65909.

It is not an unprimeable number, because it can be changed into a prime (65929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1922 + ... + 1955.

It is an arithmetic number, because the mean of its divisors is an integer number (17451).

2⁶⁵⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

65909 is a deficient number, since it is larger than the sum of its proper divisors (3895).

65909 is a wasteful number, since it uses less digits than its factorization.

65909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894.

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 65909 is about 256.7274819726. The cubic root of 65909 is about 40.3938182876.

The spelling of 65909 in words is "sixty-five thousand, nine hundred nine".