198397821636 has 192 divisors, whose sum is σ = 599721615360. Its totient is φ = 55549549440.

The previous prime is 198397821563. The next prime is 198397821641. The reversal of 198397821636 is 636128793891.

198397821636 is a `hidden beast` number, since 1 + 9 + 8 + 397 + 82 + 163 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

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 63 ways as a sum of consecutive naturals, for example, 8952826 + ... + 8974958.

It is an arithmetic number, because the mean of its divisors is an integer number (3123550080).

Almost surely, 2^198397821636 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 198397821636, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (299860807680).

198397821636 is an abundant number, since it is smaller than the sum of its proper divisors (401323793724).

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

198397821636 is a wasteful number, since it uses less digits than its factorization.

198397821636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22391 (or 22383 counting only the distinct ones).

The product of its digits is 23514624, while the sum is 63.

The spelling of 198397821636 in words is "one hundred ninety-eight billion, three hundred ninety-seven million, eight hundred twenty-one thousand, six hundred thirty-six".