198021680 has 40 divisors (see below), whose sum is σ = 461381184. Its totient is φ = 79040000.

The previous prime is 198021679. The next prime is 198021683. The reversal of 198021680 is 86120891.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 198021680.

It is not an unprimeable number, because it can be changed into a prime (198021683) 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 7 ways as a sum of consecutive naturals, for example, 39305 + ... + 44055.

Almost surely, 2^198021680 is an apocalyptic number.

198021680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

198021680 is an abundant number, since it is smaller than the sum of its proper divisors (263359504).

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

198021680 is a wasteful number, since it uses less digits than its factorization.

198021680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5285 (or 5279 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 198021680 is about 14072.0176236388. The cubic root of 198021680 is about 582.8689405074.

The spelling of 198021680 in words is "one hundred ninety-eight million, twenty-one thousand, six hundred eighty".