66501091326529 has 2 divisors, whose sum is σ = 66501091326530. Its totient is φ = 66501091326528.

The previous prime is 66501091326511. The next prime is 66501091326577. The reversal of 66501091326529 is 92562319010566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 34745071305025 + 31756020021504 = 5894495^2 + 5635248^2 .

It is a cyclic number.

It is not a de Polignac number, because 66501091326529 - 2⁴³ = 57704998304321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66501091326529.

It is not a weakly prime, because it can be changed into another prime (66501091324529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33250545663264 + 33250545663265.

It is an arithmetic number, because the mean of its divisors is an integer number (33250545663265).

Almost surely, 2^{66501091326529} is an apocalyptic number.

It is an amenable number.

66501091326529 is a deficient number, since it is larger than the sum of its proper divisors (1).

66501091326529 is an equidigital number, since it uses as much as digits as its factorization.

66501091326529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5248800, while the sum is 55.

The spelling of 66501091326529 in words is "sixty-six trillion, five hundred one billion, ninety-one million, three hundred twenty-six thousand, five hundred twenty-nine".