198924028081 has 3 divisors (see below), whose sum is σ = 198924474091. Its totient is φ = 198923582072.

The previous prime is 198924028073. The next prime is 198924028109. The reversal of 198924028081 is 180820429891.

The square root of 198924028081 is 446009.

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., 165493562481 + 33430465600 = 406809^2 + 182840^2 .

It is not a de Polignac number, because 198924028081 - 2³ = 198924028073 is a prime.

It is a super-2 number, since 2×198924028081² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198924028181) 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, 223005 + ... + 669013.

Almost surely, 2^198924028081 is an apocalyptic number.

198924028081 is the 446009-th square number.

198924028081 is the 223005-th centered octagonal number.

It is an amenable number.

198924028081 is a deficient number, since it is larger than the sum of its proper divisors (446010).

198924028081 is an frugal number, since it uses more digits than its factorization.

198924028081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892018 (or 446009 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 52.

The spelling of 198924028081 in words is "one hundred ninety-eight billion, nine hundred twenty-four million, twenty-eight thousand, eighty-one".