198963278809 has 3 divisors (see below), whose sum is σ = 198963724863. Its totient is φ = 198962832756.

The previous prime is 198963278807. The next prime is 198963278821. The reversal of 198963278809 is 908872369891.

The square root of 198963278809 is 446053.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 31214055625 + 167749223184 = 176675^2 + 409572^2 .

It is not a de Polignac number, because 198963278809 - 2¹ = 198963278807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198963278807) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 223027 + ... + 669079.

It is an arithmetic number, because the mean of its divisors is an integer number (66321241621).

Almost surely, 2^198963278809 is an apocalyptic number.

198963278809 is the 446053-rd square number.

198963278809 is the 223027-th centered octagonal number.

It is an amenable number.

198963278809 is a deficient number, since it is larger than the sum of its proper divisors (446054).

198963278809 is an frugal number, since it uses more digits than its factorization.

198963278809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892106 (or 446053 counting only the distinct ones).

The product of its (nonzero) digits is 94058496, while the sum is 70.

The spelling of 198963278809 in words is "one hundred ninety-eight billion, nine hundred sixty-three million, two hundred seventy-eight thousand, eight hundred nine".