198918669680640 has 4320 divisors, whose sum is σ = 910111236652800. Its totient is φ = 41463994908672.

The previous prime is 198918669680617. The next prime is 198918669680659. The reversal of 198918669680640 is 46086966819891.

It is a tau number, because it is divible by the number of its divisors (4320).

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 198918669680640.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 2396610478039 + ... + 2396610478121.

Almost surely, 2^{198918669680640} is an apocalyptic number.

198918669680640 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 198918669680640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (455055618326400).

198918669680640 is an abundant number, since it is smaller than the sum of its proper divisors (711192566972160).

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

198918669680640 is an frugal number, since it uses more digits than its factorization.

198918669680640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 1934917632, while the sum is 81.

The spelling of 198918669680640 in words is "one hundred ninety-eight trillion, nine hundred eighteen billion, six hundred sixty-nine million, six hundred eighty thousand, six hundred forty".