198143691 has 4 divisors (see below), whose sum is σ = 264191592. Its totient is φ = 132095792.

The previous prime is 198143629. The next prime is 198143713. The reversal of 198143691 is 196341891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 198143691 - 2¹⁹ = 197619403 is a prime.

It is a super-3 number, since 3×198143691³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (198103691) by changing a digit.

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, 33023946 + ... + 33023951.

It is an arithmetic number, because the mean of its divisors is an integer number (66047898).

Almost surely, 2^198143691 is an apocalyptic number.

198143691 is a deficient number, since it is larger than the sum of its proper divisors (66047901).

198143691 is an equidigital number, since it uses as much as digits as its factorization.

198143691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66047900.

The product of its digits is 46656, while the sum is 42.

The square root of 198143691 is about 14076.3521908199. The cubic root of 198143691 is about 582.9886274380.

The spelling of 198143691 in words is "one hundred ninety-eight million, one hundred forty-three thousand, six hundred ninety-one".