666791817762 has 128 divisors (see below), whose sum is σ = 1610336931840. Its totient is φ = 179808491520.

The previous prime is 666791817733. The next prime is 666791817793. The reversal of 666791817762 is 267718197666.

It is a super-2 number, since 2×666791817762² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 666791817693 and 666791817702.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 450230062 + ... + 450231542.

It is an arithmetic number, because the mean of its divisors is an integer number (12580757280).

Almost surely, 2^666791817762 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666791817762, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (805168465920).

666791817762 is an abundant number, since it is smaller than the sum of its proper divisors (943545114078).

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

666791817762 is a wasteful number, since it uses less digits than its factorization.

666791817762 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3248.

The product of its digits is 64012032, while the sum is 66.

The spelling of 666791817762 in words is "six hundred sixty-six billion, seven hundred ninety-one million, eight hundred seventeen thousand, seven hundred sixty-two".