65840309 has 2 divisors, whose sum is σ = 65840310. Its totient is φ = 65840308.

The previous prime is 65840287. The next prime is 65840347. The reversal of 65840309 is 90304856.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49210225 + 16630084 = 7015^2 + 4078^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65840309 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65840389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32920154 + 32920155.

It is an arithmetic number, because the mean of its divisors is an integer number (32920155).

Almost surely, 2^65840309 is an apocalyptic number.

It is an amenable number.

65840309 is a deficient number, since it is larger than the sum of its proper divisors (1).

65840309 is an equidigital number, since it uses as much as digits as its factorization.

65840309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 65840309 is about 8114.2041507470. The cubic root of 65840309 is about 403.7978046640.

The spelling of 65840309 in words is "sixty-five million, eight hundred forty thousand, three hundred nine".