191089 has 2 divisors, whose sum is σ = 191090. Its totient is φ = 191088.

The previous prime is 191071. The next prime is 191099. The reversal of 191089 is 980191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 187489 + 3600 = 433^2 + 60^2 .

It is a cyclic number.

It is not a de Polignac number, because 191089 - 2⁵ = 191057 is a prime.

It is a Chen prime.

It is a nialpdrome in base 9.

It is not a weakly prime, because it can be changed into another prime (191039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95544 + 95545.

It is an arithmetic number, because the mean of its divisors is an integer number (95545).

2¹⁹¹⁰⁸⁹ is an apocalyptic number.

It is an amenable number.

191089 is a deficient number, since it is larger than the sum of its proper divisors (1).

191089 is an equidigital number, since it uses as much as digits as its factorization.

191089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 191089 is about 437.1372782090. The cubic root of 191089 is about 57.5985958055.

The spelling of 191089 in words is "one hundred ninety-one thousand, eighty-nine".