198187903489 has 3 divisors (see below), whose sum is σ = 198188348673. Its totient is φ = 198187458306.

The previous prime is 198187903457. The next prime is 198187903513. The reversal of 198187903489 is 984309781891.

The square root of 198187903489 is 445183.

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, and also an emirpimes, since its reverse is a distinct semiprime: 984309781891 = 179 ⋅5498937329.

It is not a de Polignac number, because 198187903489 - 2⁵ = 198187903457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198187903289) by changing a digit.

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 in 2 ways as a sum of consecutive naturals, for example, 222592 + ... + 667774.

It is an arithmetic number, because the mean of its divisors is an integer number (66062782891).

Almost surely, 2^198187903489 is an apocalyptic number.

198187903489 is the 445183-rd square number.

198187903489 is the 222592-nd centered octagonal number.

It is an amenable number.

198187903489 is a deficient number, since it is larger than the sum of its proper divisors (445184).

198187903489 is an frugal number, since it uses more digits than its factorization.

198187903489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890366 (or 445183 counting only the distinct ones).

The product of its (nonzero) digits is 31352832, while the sum is 67.

The spelling of 198187903489 in words is "one hundred ninety-eight billion, one hundred eighty-seven million, nine hundred three thousand, four hundred eighty-nine".