65409 has 4 divisors (see below), whose sum is σ = 87216. Its totient is φ = 43604.

The previous prime is 65407. The next prime is 65413. The reversal of 65409 is 90456.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65409 - 2¹ = 65407 is a prime.

It is a D-number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (65407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10899 + ... + 10904.

It is an arithmetic number, because the mean of its divisors is an integer number (21804).

2⁶⁵⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

65409 is a deficient number, since it is larger than the sum of its proper divisors (21807).

65409 is a wasteful number, since it uses less digits than its factorization.

65409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21806.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 65409 is about 255.7518328380. The cubic root of 65409 is about 40.2914134658.

It can be divided in two parts, 65 and 409, that added together give a palindrome (474).

The spelling of 65409 in words is "sixty-five thousand, four hundred nine".