198809840 has 20 divisors (see below), whose sum is σ = 462233064. Its totient is φ = 79523904.

The previous prime is 198809777. The next prime is 198809867. The reversal of 198809840 is 48908891.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1242482 + ... + 1242641.

Almost surely, 2^198809840 is an apocalyptic number.

198809840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

198809840 is an abundant number, since it is smaller than the sum of its proper divisors (263423224).

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

198809840 is a wasteful number, since it uses less digits than its factorization.

198809840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2485136 (or 2485130 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 47.

The square root of 198809840 is about 14099.9943262400. The cubic root of 198809840 is about 583.6412226797.

The spelling of 198809840 in words is "one hundred ninety-eight million, eight hundred nine thousand, eight hundred forty".