191087 has 4 divisors (see below), whose sum is σ = 205800. Its totient is φ = 176376.

The previous prime is 191071. The next prime is 191089. The reversal of 191087 is 780191.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 191087 - 2⁴ = 191071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7337 + ... + 7362.

It is an arithmetic number, because the mean of its divisors is an integer number (51450).

2¹⁹¹⁰⁸⁷ is an apocalyptic number.

191087 is a deficient number, since it is larger than the sum of its proper divisors (14713).

191087 is a wasteful number, since it uses less digits than its factorization.

191087 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14712.

The product of its (nonzero) digits is 504, while the sum is 26.

The square root of 191087 is about 437.1349905922. The cubic root of 191087 is about 57.5983948562.

The spelling of 191087 in words is "one hundred ninety-one thousand, eighty-seven".