191288189 has 2 divisors, whose sum is σ = 191288190. Its totient is φ = 191288188.

The previous prime is 191288177. The next prime is 191288213. The reversal of 191288189 is 981882191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128640964 + 62647225 = 11342^2 + 7915^2 .

It is an emirp because it is prime and its reverse (981882191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191288189 - 2⁴ = 191288173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191288389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95644094 + 95644095.

It is an arithmetic number, because the mean of its divisors is an integer number (95644095).

Almost surely, 2^191288189 is an apocalyptic number.

It is an amenable number.

191288189 is a deficient number, since it is larger than the sum of its proper divisors (1).

191288189 is an equidigital number, since it uses as much as digits as its factorization.

191288189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 82944, while the sum is 47.

The square root of 191288189 is about 13830.6973432289. The cubic root of 191288189 is about 576.1860222935.

The spelling of 191288189 in words is "one hundred ninety-one million, two hundred eighty-eight thousand, one hundred eighty-nine".