198368993 has 4 divisors (see below), whose sum is σ = 198673428. Its totient is φ = 198064560.

The previous prime is 198368957. The next prime is 198369001. The reversal of 198368993 is 399863891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 399863891 = 7 ⋅57123413.

It can be written as a sum of positive squares in 2 ways, for example, as 72301009 + 126067984 = 8503^2 + 11228^2 .

It is a cyclic number.

It is not a de Polignac number, because 198368993 - 2¹⁸ = 198106849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (198368293) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 151238 + ... + 152543.

It is an arithmetic number, because the mean of its divisors is an integer number (49668357).

Almost surely, 2^198368993 is an apocalyptic number.

It is an amenable number.

198368993 is a deficient number, since it is larger than the sum of its proper divisors (304435).

198368993 is an equidigital number, since it uses as much as digits as its factorization.

198368993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304434.

The product of its digits is 2519424, while the sum is 56.

The square root of 198368993 is about 14084.3527717819. The cubic root of 198368993 is about 583.2095088105.

The spelling of 198368993 in words is "one hundred ninety-eight million, three hundred sixty-eight thousand, nine hundred ninety-three".