198995666 has 4 divisors (see below), whose sum is σ = 298493502. Its totient is φ = 99497832.

The previous prime is 198995653. The next prime is 198995677. The reversal of 198995666 is 666599891.

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., 194463025 + 4532641 = 13945^2 + 2129^2 .

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, 49748915 + ... + 49748918.

Almost surely, 2^198995666 is an apocalyptic number.

198995666 is a deficient number, since it is larger than the sum of its proper divisors (99497836).

198995666 is an equidigital number, since it uses as much as digits as its factorization.

198995666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99497835.

The product of its digits is 6298560, while the sum is 59.

The square root of 198995666 is about 14106.5823642724. The cubic root of 198995666 is about 583.8230076800.

The spelling of 198995666 in words is "one hundred ninety-eight million, nine hundred ninety-five thousand, six hundred sixty-six".