65840861 has 2 divisors, whose sum is σ = 65840862. Its totient is φ = 65840860.

The previous prime is 65840857. The next prime is 65840867. The reversal of 65840861 is 16804856.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64802500 + 1038361 = 8050^2 + 1019^2 .

It is a cyclic number.

It is not a de Polignac number, because 65840861 - 2² = 65840857 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 (65840867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32920430 + 32920431.

It is an arithmetic number, because the mean of its divisors is an integer number (32920431).

Almost surely, 2^65840861 is an apocalyptic number.

It is an amenable number.

65840861 is a deficient number, since it is larger than the sum of its proper divisors (1).

65840861 is an equidigital number, since it uses as much as digits as its factorization.

65840861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46080, while the sum is 38.

The square root of 65840861 is about 8114.2381651021. The cubic root of 65840861 is about 403.7989331306.

The spelling of 65840861 in words is "sixty-five million, eight hundred forty thousand, eight hundred sixty-one".