195188891 has 2 divisors, whose sum is σ = 195188892. Its totient is φ = 195188890.

The previous prime is 195188857. The next prime is 195188893. The reversal of 195188891 is 198881591.

195188891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 195188891 - 2¹⁴ = 195172507 is a prime.

Together with 195188893, 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 (195188893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97594445 + 97594446.

It is an arithmetic number, because the mean of its divisors is an integer number (97594446).

Almost surely, 2^195188891 is an apocalyptic number.

195188891 is a deficient number, since it is larger than the sum of its proper divisors (1).

195188891 is an equidigital number, since it uses as much as digits as its factorization.

195188891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 50.

The square root of 195188891 is about 13971.0017894208. The cubic root of 195188891 is about 580.0761800452.

Subtracting from 195188891 its sum of digits (50), we obtain a square (195188841 = 13971²).

The spelling of 195188891 in words is "one hundred ninety-five million, one hundred eighty-eight thousand, eight hundred ninety-one".