64661818884191 has 2 divisors, whose sum is σ = 64661818884192. Its totient is φ = 64661818884190.

The previous prime is 64661818884161. The next prime is 64661818884217. The reversal of 64661818884191 is 19148881816646.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64661818884191 - 2⁶ = 64661818884127 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64661818884161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32330909442095 + 32330909442096.

It is an arithmetic number, because the mean of its divisors is an integer number (32330909442096).

Almost surely, 2^{64661818884191} is an apocalyptic number.

64661818884191 is a deficient number, since it is larger than the sum of its proper divisors (1).

64661818884191 is an equidigital number, since it uses as much as digits as its factorization.

64661818884191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 127401984, while the sum is 71.

The spelling of 64661818884191 in words is "sixty-four trillion, six hundred sixty-one billion, eight hundred eighteen million, eight hundred eighty-four thousand, one hundred ninety-one".