198181089 has 12 divisors (see below), whose sum is σ = 289097172. Its totient is φ = 130812000.

The previous prime is 198181079. The next prime is 198181091. The reversal of 198181089 is 980181891.

It can be written as a sum of positive squares in 2 ways, for example, as 139428864 + 58752225 = 11808^2 + 7665^2 .

It is not a de Polignac number, because 198181089 - 2⁴ = 198181073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198181079) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 108102 + ... + 109919.

It is an arithmetic number, because the mean of its divisors is an integer number (24091431).

Almost surely, 2^198181089 is an apocalyptic number.

It is an amenable number.

198181089 is a deficient number, since it is larger than the sum of its proper divisors (90916083).

198181089 is a wasteful number, since it uses less digits than its factorization.

198181089 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218128 (or 218125 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 45.

The square root of 198181089 is about 14077.6805262799. The cubic root of 198181089 is about 583.0253032413.

The spelling of 198181089 in words is "one hundred ninety-eight million, one hundred eighty-one thousand, eighty-nine".