198645091 has 2 divisors, whose sum is σ = 198645092. Its totient is φ = 198645090.

The previous prime is 198645067. The next prime is 198645101. The reversal of 198645091 is 190546891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 198645091 - 2⁵ = 198645059 is a prime.

It is not a weakly prime, because it can be changed into another prime (198645791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99322545 + 99322546.

It is an arithmetic number, because the mean of its divisors is an integer number (99322546).

Almost surely, 2^198645091 is an apocalyptic number.

198645091 is a deficient number, since it is larger than the sum of its proper divisors (1).

198645091 is an equidigital number, since it uses as much as digits as its factorization.

198645091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 198645091 is about 14094.1509499508. The cubic root of 198645091 is about 583.4799615799.

The spelling of 198645091 in words is "one hundred ninety-eight million, six hundred forty-five thousand, ninety-one".