197986 has 4 divisors (see below), whose sum is σ = 296982. Its totient is φ = 98992.

The previous prime is 197971. The next prime is 198013. The reversal of 197986 is 689791.

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., 119025 + 78961 = 345^2 + 281^2 .

It is a Smith number, since the sum of its digits (40) 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 (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49495 + ... + 49498.

2¹⁹⁷⁹⁸⁶ is an apocalyptic number.

197986 is a deficient number, since it is larger than the sum of its proper divisors (98996).

197986 is an equidigital number, since it uses as much as digits as its factorization.

197986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98995.

The product of its digits is 27216, while the sum is 40.

The square root of 197986 is about 444.9561776175. The cubic root of 197986 is about 58.2833930851.

The spelling of 197986 in words is "one hundred ninety-seven thousand, nine hundred eighty-six".