198128387 has 8 divisors (see below), whose sum is σ = 212312016. Its totient is φ = 184225792.

The previous prime is 198128383. The next prime is 198128393. The reversal of 198128387 is 783821891.

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 198128387 - 2² = 198128383 is a prime.

It is a super-3 number, since 3×198128387³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198128383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68798 + ... + 71619.

It is an arithmetic number, because the mean of its divisors is an integer number (26539002).

Almost surely, 2^198128387 is an apocalyptic number.

198128387 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

198128387 is a deficient number, since it is larger than the sum of its proper divisors (14183629).

198128387 is a wasteful number, since it uses less digits than its factorization.

198128387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140517.

The product of its digits is 193536, while the sum is 47.

The square root of 198128387 is about 14075.8085735776. The cubic root of 198128387 is about 582.9736176445.

It can be divided in two parts, 198128 and 387, that multiplied together give a triangular number (76675536 = T₁₂₃₈₃).

The spelling of 198128387 in words is "one hundred ninety-eight million, one hundred twenty-eight thousand, three hundred eighty-seven".