666194 has 4 divisors (see below), whose sum is σ = 999294. Its totient is φ = 333096.

The previous prime is 666191. The next prime is 666203. The reversal of 666194 is 491666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 429025 + 237169 = 655^2 + 487^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 666194.

It is not an unprimeable number, because it can be changed into a prime (666191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166547 + ... + 166550.

2⁶⁶⁶¹⁹⁴ is an apocalyptic number.

666194 is a deficient number, since it is larger than the sum of its proper divisors (333100).

666194 is a wasteful number, since it uses less digits than its factorization.

666194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333099.

The product of its digits is 7776, while the sum is 32.

The square root of 666194 is about 816.2070815669. The cubic root of 666194 is about 87.3373959741.

It can be divided in two parts, 66 and 6194, that multiplied together give a palindrome (408804).

The spelling of 666194 in words is "six hundred sixty-six thousand, one hundred ninety-four".