198764221 has 4 divisors (see below), whose sum is σ = 210456252. Its totient is φ = 187072192.

The previous prime is 198764213. The next prime is 198764239. The reversal of 198764221 is 122467891.

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

It can be written as a sum of positive squares in 2 ways, for example, as 147355321 + 51408900 = 12139^2 + 7170^2 .

It is a cyclic number.

It is not a de Polignac number, because 198764221 - 2³ = 198764213 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 (198764021) 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, 5845990 + ... + 5846023.

It is an arithmetic number, because the mean of its divisors is an integer number (52614063).

Almost surely, 2^198764221 is an apocalyptic number.

It is an amenable number.

198764221 is a deficient number, since it is larger than the sum of its proper divisors (11692031).

198764221 is a wasteful number, since it uses less digits than its factorization.

198764221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11692030.

The product of its digits is 48384, while the sum is 40.

The square root of 198764221 is about 14098.3765377436. The cubic root of 198764221 is about 583.5965784010.

The spelling of 198764221 in words is "one hundred ninety-eight million, seven hundred sixty-four thousand, two hundred twenty-one".