198561963636 has 72 divisors (see below), whose sum is σ = 536707256904. Its totient is φ = 61677158400.

The previous prime is 198561963629. The next prime is 198561963661. The reversal of 198561963636 is 636369165891.

198561963636 is a `hidden beast` number, since 1 + 9 + 8 + 5 + 619 + 6 + 3 + 6 + 3 + 6 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 173518901136 + 25043062500 = 416556^2 + 158250^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1544365 + ... + 1667988.

It is an arithmetic number, because the mean of its divisors is an integer number (7454267457).

Almost surely, 2^198561963636 is an apocalyptic number.

It is an amenable number.

198561963636 is an abundant number, since it is smaller than the sum of its proper divisors (338145293268).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198561963636 is a wasteful number, since it uses less digits than its factorization.

198561963636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3212481 (or 3212476 counting only the distinct ones).

The product of its digits is 37791360, while the sum is 63.

The spelling of 198561963636 in words is "one hundred ninety-eight billion, five hundred sixty-one million, nine hundred sixty-three thousand, six hundred thirty-six".