197979986 has 4 divisors (see below), whose sum is σ = 296969982. Its totient is φ = 98989992.

The previous prime is 197979973. The next prime is 197980001. The reversal of 197979986 is 689979791.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689979791 = 15101 ⋅45691.

It can be written as a sum of positive squares in only one way, i.e., 180499225 + 17480761 = 13435^2 + 4181^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49494995 + ... + 49494998.

Almost surely, 2^197979986 is an apocalyptic number.

197979986 is a deficient number, since it is larger than the sum of its proper divisors (98989996).

197979986 is an equidigital number, since it uses as much as digits as its factorization.

197979986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98989995.

The product of its digits is 15431472, while the sum is 65.

The square root of 197979986 is about 14070.5360949752. The cubic root of 197979986 is about 582.8280294257.

The spelling of 197979986 in words is "one hundred ninety-seven million, nine hundred seventy-nine thousand, nine hundred eighty-six".