666942 has 16 divisors (see below), whose sum is σ = 1380240. Its totient is φ = 214592.

The previous prime is 666937. The next prime is 666959. The reversal of 666942 is 249666.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable 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 7 ways as a sum of consecutive naturals, for example, 1743 + ... + 2090.

It is an arithmetic number, because the mean of its divisors is an integer number (86265).

2⁶⁶⁶⁹⁴² is an apocalyptic number.

666942 is an abundant number, since it is smaller than the sum of its proper divisors (713298).

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

666942 is a wasteful number, since it uses less digits than its factorization.

666942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3867.

The product of its digits is 15552, while the sum is 33.

The square root of 666942 is about 816.6651700667. The cubic root of 666942 is about 87.3700711095.

The spelling of 666942 in words is "six hundred sixty-six thousand, nine hundred forty-two".