666791817792 has 112 divisors (see below), whose sum is σ = 1775589430272. Its totient is φ = 220832801280.

The previous prime is 666791817733. The next prime is 666791817793. The reversal of 666791817792 is 297718197666.

It is a happy number.

It is a super-2 number, since 2×666791817792² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666791817793) 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, 112573743 + ... + 112579665.

It is an arithmetic number, because the mean of its divisors is an integer number (15853477056).

Almost surely, 2^666791817792 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666791817792, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (887794715136).

666791817792 is an abundant number, since it is smaller than the sum of its proper divisors (1108797612480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666791817792 is a wasteful number, since it uses less digits than its factorization.

666791817792 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9616 (or 9606 counting only the distinct ones).

The product of its digits is 96018048, while the sum is 69.

The spelling of 666791817792 in words is "six hundred sixty-six billion, seven hundred ninety-one million, eight hundred seventeen thousand, seven hundred ninety-two".