65218309 has 8 divisors (see below), whose sum is σ = 72133880. Its totient is φ = 58574016.

The previous prime is 65218301. The next prime is 65218313. The reversal of 65218309 is 90381256.

65218309 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 29398084 + 35820225 = 5422^2 + 5985^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65218309 - 2³ = 65218301 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65218301) 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 7 ways as a sum of consecutive naturals, for example, 67314 + ... + 68275.

It is an arithmetic number, because the mean of its divisors is an integer number (9016735).

Almost surely, 2^65218309 is an apocalyptic number.

It is an amenable number.

65218309 is a deficient number, since it is larger than the sum of its proper divisors (6915571).

65218309 is a wasteful number, since it uses less digits than its factorization.

65218309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135639.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 65218309 is about 8075.7853488066. The cubic root of 65218309 is about 402.5222065086.

The spelling of 65218309 in words is "sixty-five million, two hundred eighteen thousand, three hundred nine".