65409209 has 4 divisors (see below), whose sum is σ = 65619840. Its totient is φ = 65198580.

The previous prime is 65409203. The next prime is 65409221. The reversal of 65409209 is 90290456.

65409209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 65409209 - 2⁴ = 65409193 is a prime.

It is a super-3 number, since 3×65409209³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65409203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104849 + ... + 105470.

It is an arithmetic number, because the mean of its divisors is an integer number (16404960).

Almost surely, 2^65409209 is an apocalyptic number.

It is an amenable number.

65409209 is a deficient number, since it is larger than the sum of its proper divisors (210631).

65409209 is a wasteful number, since it uses less digits than its factorization.

65409209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210630.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 65409209 is about 8087.5959963391. The cubic root of 65409209 is about 402.9145637982.

The spelling of 65409209 in words is "sixty-five million, four hundred nine thousand, two hundred nine".