65817878213 has 2 divisors, whose sum is σ = 65817878214. Its totient is φ = 65817878212.

The previous prime is 65817878183. The next prime is 65817878237. The reversal of 65817878213 is 31287871856.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58785881764 + 7031996449 = 242458^2 + 83857^2 .

It is a cyclic number.

It is not a de Polignac number, because 65817878213 - 2¹⁰ = 65817877189 is a prime.

It is a super-2 number, since 2×65817878213² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85817878213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32908939106 + 32908939107.

It is an arithmetic number, because the mean of its divisors is an integer number (32908939107).

Almost surely, 2^65817878213 is an apocalyptic number.

It is an amenable number.

65817878213 is a deficient number, since it is larger than the sum of its proper divisors (1).

65817878213 is an equidigital number, since it uses as much as digits as its factorization.

65817878213 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4515840, while the sum is 56.

The spelling of 65817878213 in words is "sixty-five billion, eight hundred seventeen million, eight hundred seventy-eight thousand, two hundred thirteen".