664643044859 has 2 divisors, whose sum is σ = 664643044860. Its totient is φ = 664643044858.

The previous prime is 664643044837. The next prime is 664643044861. The reversal of 664643044859 is 958440346466.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664643044859 is a prime.

Together with 664643044861, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 664643044798 and 664643044807.

It is not a weakly prime, because it can be changed into another prime (664643044889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332321522429 + 332321522430.

It is an arithmetic number, because the mean of its divisors is an integer number (332321522430).

Almost surely, 2^664643044859 is an apocalyptic number.

664643044859 is a deficient number, since it is larger than the sum of its proper divisors (1).

664643044859 is an equidigital number, since it uses as much as digits as its factorization.

664643044859 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 59719680, while the sum is 59.

The spelling of 664643044859 in words is "six hundred sixty-four billion, six hundred forty-three million, forty-four thousand, eight hundred fifty-nine".