666846 has 32 divisors (see below), whose sum is σ = 1516320. Its totient is φ = 217152.

The previous prime is 666829. The next prime is 666857. The reversal of 666846 is 648666.

It is a self number, because there is not a number n which added to its sum of digits gives 666846.

It is a congruent number.

It is an unprimeable number.

666846 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2746 + ... + 2978.

It is an arithmetic number, because the mean of its divisors is an integer number (47385).

2⁶⁶⁶⁸⁴⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (758160).

666846 is an abundant number, since it is smaller than the sum of its proper divisors (849474).

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

666846 is a wasteful number, since it uses less digits than its factorization.

666846 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297 (or 291 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 666846 is about 816.6063923335. The cubic root of 666846 is about 87.3658788762.

The spelling of 666846 in words is "six hundred sixty-six thousand, eight hundred forty-six".