199436891 has 2 divisors, whose sum is σ = 199436892. Its totient is φ = 199436890.

The previous prime is 199436873. The next prime is 199436893. The reversal of 199436891 is 198634991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199436891 is a prime.

Together with 199436893, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199436893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99718445 + 99718446.

It is an arithmetic number, because the mean of its divisors is an integer number (99718446).

Almost surely, 2^199436891 is an apocalyptic number.

199436891 is a deficient number, since it is larger than the sum of its proper divisors (1).

199436891 is an equidigital number, since it uses as much as digits as its factorization.

199436891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 419904, while the sum is 50.

The square root of 199436891 is about 14122.2126807381. The cubic root of 199436891 is about 584.2541848328.

The spelling of 199436891 in words is "one hundred ninety-nine million, four hundred thirty-six thousand, eight hundred ninety-one".