198689187840 has 768 divisors, whose sum is σ = 771395788800. Its totient is φ = 42998169600.

The previous prime is 198689187839. The next prime is 198689187847. The reversal of 198689187840 is 48781986891.

It is a tau number, because it is divible by the number of its divisors (768).

It is not an unprimeable number, because it can be changed into a prime (198689187847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 136181031 + ... + 136182489.

It is an arithmetic number, because the mean of its divisors is an integer number (1004421600).

Almost surely, 2^198689187840 is an apocalyptic number.

198689187840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 198689187840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (385697894400).

198689187840 is an abundant number, since it is smaller than the sum of its proper divisors (572706600960).

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

198689187840 is a wasteful number, since it uses less digits than its factorization.

198689187840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1544 (or 1524 counting only the distinct ones).

The product of its (nonzero) digits is 55738368, while the sum is 69.

The spelling of 198689187840 in words is "one hundred ninety-eight billion, six hundred eighty-nine million, one hundred eighty-seven thousand, eight hundred forty".