197666 has 12 divisors (see below), whose sum is σ = 345078. Its totient is φ = 84672.

The previous prime is 197651. The next prime is 197677. The reversal of 197666 is 666791.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 137641 + 60025 = 371^2 + 245^2 .

It is a plaindrome in base 11.

It is an unprimeable number.

197666 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 (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 911 + ... + 1106.

2¹⁹⁷⁶⁶⁶ is an apocalyptic number.

197666 is a deficient number, since it is larger than the sum of its proper divisors (147412).

197666 is a wasteful number, since it uses less digits than its factorization.

197666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2033 (or 2026 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 197666 is about 444.5964462296. The cubic root of 197666 is about 58.2519754713.

The spelling of 197666 in words is "one hundred ninety-seven thousand, six hundred sixty-six".