198907081 has 2 divisors, whose sum is σ = 198907082. Its totient is φ = 198907080.

The previous prime is 198907063. The next prime is 198907087. The reversal of 198907081 is 180709891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179024400 + 19882681 = 13380^2 + 4459^2 .

It is a cyclic number.

It is not a de Polignac number, because 198907081 - 2⁹ = 198906569 is a prime.

It is a super-2 number, since 2×198907081² = 79128053743881122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (198907087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99453540 + 99453541.

It is an arithmetic number, because the mean of its divisors is an integer number (99453541).

Almost surely, 2^198907081 is an apocalyptic number.

It is an amenable number.

198907081 is a deficient number, since it is larger than the sum of its proper divisors (1).

198907081 is an equidigital number, since it uses as much as digits as its factorization.

198907081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 43.

The square root of 198907081 is about 14103.4421684921. The cubic root of 198907081 is about 583.7363631844.

The spelling of 198907081 in words is "one hundred ninety-eight million, nine hundred seven thousand, eighty-one".