197666843 has 4 divisors (see below), whose sum is σ = 215636568. Its totient is φ = 179697120.

The previous prime is 197666809. The next prime is 197666857. The reversal of 197666843 is 348666791.

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

It is a cyclic number.

It is not a de Polignac number, because 197666843 - 2²⁴ = 180889627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 197666791 and 197666800.

It is not an unprimeable number, because it can be changed into a prime (197666873) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8984846 + ... + 8984867.

It is an arithmetic number, because the mean of its divisors is an integer number (53909142).

Almost surely, 2^197666843 is an apocalyptic number.

197666843 is a deficient number, since it is larger than the sum of its proper divisors (17969725).

197666843 is a wasteful number, since it uses less digits than its factorization.

197666843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17969724.

The product of its digits is 1306368, while the sum is 50.

The square root of 197666843 is about 14059.4040769870. The cubic root of 197666843 is about 582.5205828163.

The spelling of 197666843 in words is "one hundred ninety-seven million, six hundred sixty-six thousand, eight hundred forty-three".