666791817807 has 8 divisors (see below), whose sum is σ = 897687366784. Its totient is φ = 440212073688.

The previous prime is 666791817799. The next prime is 666791817817. The reversal of 666791817807 is 708718197666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 666791817807 - 2³ = 666791817799 is a prime.

It is a super-2 number, since 2×666791817807² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666791817817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1078950853 + ... + 1078951470.

It is an arithmetic number, because the mean of its divisors is an integer number (112210920848).

Almost surely, 2^666791817807 is an apocalyptic number.

666791817807 is a deficient number, since it is larger than the sum of its proper divisors (230895548977).

666791817807 is a wasteful number, since it uses less digits than its factorization.

666791817807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2157902429.

The product of its (nonzero) digits is 42674688, while the sum is 66.

The spelling of 666791817807 in words is "six hundred sixty-six billion, seven hundred ninety-one million, eight hundred seventeen thousand, eight hundred seven".