666791817782 has 32 divisors (see below), whose sum is σ = 1021875886080. Its totient is φ = 326202196320.

The previous prime is 666791817733. The next prime is 666791817793. The reversal of 666791817782 is 287718197666.

It is a super-2 number, since 2×666791817782² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113416319 + ... + 113422197.

It is an arithmetic number, because the mean of its divisors is an integer number (31933621440).

Almost surely, 2^666791817782 is an apocalyptic number.

666791817782 is a deficient number, since it is larger than the sum of its proper divisors (355084068298).

666791817782 is a wasteful number, since it uses less digits than its factorization.

666791817782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8708.

The product of its digits is 85349376, while the sum is 68.

The spelling of 666791817782 in words is "six hundred sixty-six billion, seven hundred ninety-one million, eight hundred seventeen thousand, seven hundred eighty-two".