66510172516217 has 4 divisors (see below), whose sum is σ = 68655661952256. Its totient is φ = 64364683080180.

The previous prime is 66510172516201. The next prime is 66510172516273. The reversal of 66510172516217 is 71261527101566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66510172516217 - 2⁴ = 66510172516201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66510172518217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1072744717973 + ... + 1072744718034.

It is an arithmetic number, because the mean of its divisors is an integer number (17163915488064).

Almost surely, 2^{66510172516217} is an apocalyptic number.

It is an amenable number.

66510172516217 is a deficient number, since it is larger than the sum of its proper divisors (2145489436039).

66510172516217 is a wasteful number, since it uses less digits than its factorization.

66510172516217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2145489436038.

The product of its (nonzero) digits is 1058400, while the sum is 50.

The spelling of 66510172516217 in words is "sixty-six trillion, five hundred ten billion, one hundred seventy-two million, five hundred sixteen thousand, two hundred seventeen".