664416317402561 has 2 divisors, whose sum is σ = 664416317402562. Its totient is φ = 664416317402560.

The previous prime is 664416317402549. The next prime is 664416317402609. The reversal of 664416317402561 is 165204713614466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 423957983257600 + 240458334144961 = 20590240^2 + 15506719^2 .

It is a cyclic number.

It is not a de Polignac number, because 664416317402561 - 2¹⁴ = 664416317386177 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 664416317402497 and 664416317402506.

It is not a weakly prime, because it can be changed into another prime (664418317402561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332208158701280 + 332208158701281.

It is an arithmetic number, because the mean of its divisors is an integer number (332208158701281).

Almost surely, 2^{664416317402561} is an apocalyptic number.

It is an amenable number.

664416317402561 is a deficient number, since it is larger than the sum of its proper divisors (1).

664416317402561 is an equidigital number, since it uses as much as digits as its factorization.

664416317402561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17418240, while the sum is 56.

The spelling of 664416317402561 in words is "six hundred sixty-four trillion, four hundred sixteen billion, three hundred seventeen million, four hundred two thousand, five hundred sixty-one".