198905645 has 8 divisors (see below), whose sum is σ = 243765504. Its totient is φ = 155738704.

The previous prime is 198905621. The next prime is 198905711. The reversal of 198905645 is 546509891.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 198905645 - 2²⁰ = 197857069 is a prime.

It is a super-3 number, since 3×198905645³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 198905645.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 422969 + ... + 423438.

It is an arithmetic number, because the mean of its divisors is an integer number (30470688).

Almost surely, 2^198905645 is an apocalyptic number.

It is an amenable number.

198905645 is a deficient number, since it is larger than the sum of its proper divisors (44859859).

198905645 is an equidigital number, since it uses as much as digits as its factorization.

198905645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846459.

The product of its (nonzero) digits is 388800, while the sum is 47.

The square root of 198905645 is about 14103.3912588427. The cubic root of 198905645 is about 583.7349584289.

The spelling of 198905645 in words is "one hundred ninety-eight million, nine hundred five thousand, six hundred forty-five".