66808501810973 has 16 divisors (see below), whose sum is σ = 72105952017456. Its totient is φ = 61533760458240.

The previous prime is 66808501810877. The next prime is 66808501810979. The reversal of 66808501810973 is 37901810580866.

It can be written as a sum of positive squares in 8 ways, for example, as 5075707102489 + 61732794708484 = 2252933^2 + 7857022^2 .

It is a cyclic number.

It is not a de Polignac number, because 66808501810973 - 2¹⁰ = 66808501809949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66808501810979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16041563 + ... + 19772423.

It is an arithmetic number, because the mean of its divisors is an integer number (4506622001091).

Almost surely, 2^{66808501810973} is an apocalyptic number.

It is an amenable number.

66808501810973 is a deficient number, since it is larger than the sum of its proper divisors (5297450206483).

66808501810973 is a wasteful number, since it uses less digits than its factorization.

66808501810973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3733904.

The product of its (nonzero) digits is 17418240, while the sum is 62.

The spelling of 66808501810973 in words is "sixty-six trillion, eight hundred eight billion, five hundred one million, eight hundred ten thousand, nine hundred seventy-three".