198155638 has 8 divisors (see below), whose sum is σ = 314717832. Its totient is φ = 93249696.

The previous prime is 198155599. The next prime is 198155641. The reversal of 198155638 is 836551891.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2914020 + ... + 2914087.

It is an arithmetic number, because the mean of its divisors is an integer number (39339729).

Almost surely, 2^198155638 is an apocalyptic number.

198155638 is a deficient number, since it is larger than the sum of its proper divisors (116562194).

198155638 is a wasteful number, since it uses less digits than its factorization.

198155638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5828126.

The product of its digits is 259200, while the sum is 46.

The square root of 198155638 is about 14076.7765486279. The cubic root of 198155638 is about 583.0003442298. Note that the first 3 decimals are identical.

The spelling of 198155638 in words is "one hundred ninety-eight million, one hundred fifty-five thousand, six hundred thirty-eight".