198721663 has 4 divisors (see below), whose sum is σ = 227110480. Its totient is φ = 170332848.

The previous prime is 198721661. The next prime is 198721667. The reversal of 198721663 is 366127891.

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

It is not a de Polignac number, because 198721663 - 2¹ = 198721661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198721661) 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, 14194398 + ... + 14194411.

It is an arithmetic number, because the mean of its divisors is an integer number (56777620).

Almost surely, 2^198721663 is an apocalyptic number.

198721663 is a deficient number, since it is larger than the sum of its proper divisors (28388817).

198721663 is an equidigital number, since it uses as much as digits as its factorization.

198721663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28388816.

The product of its digits is 108864, while the sum is 43.

The square root of 198721663 is about 14096.8671342252. The cubic root of 198721663 is about 583.5549235601.

The spelling of 198721663 in words is "one hundred ninety-eight million, seven hundred twenty-one thousand, six hundred sixty-three".