198734891 has 2 divisors, whose sum is σ = 198734892. Its totient is φ = 198734890.

The previous prime is 198734873. The next prime is 198734897. The reversal of 198734891 is 198437891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 198734891 - 2²² = 194540587 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (198734897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99367445 + 99367446.

It is an arithmetic number, because the mean of its divisors is an integer number (99367446).

Almost surely, 2^198734891 is an apocalyptic number.

198734891 is a deficient number, since it is larger than the sum of its proper divisors (1).

198734891 is an equidigital number, since it uses as much as digits as its factorization.

198734891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 50.

The square root of 198734891 is about 14097.3363086790. The cubic root of 198734891 is about 583.5678714745.

The spelling of 198734891 in words is "one hundred ninety-eight million, seven hundred thirty-four thousand, eight hundred ninety-one".