191006087 has 4 divisors (see below), whose sum is σ = 191050776. Its totient is φ = 190961400.

The previous prime is 191006077. The next prime is 191006089. The reversal of 191006087 is 780600191.

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 191006087 - 2⁴ = 191006071 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 (191006089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15164 + ... + 24737.

It is an arithmetic number, because the mean of its divisors is an integer number (47762694).

Almost surely, 2^191006087 is an apocalyptic number.

191006087 is a deficient number, since it is larger than the sum of its proper divisors (44689).

191006087 is an equidigital number, since it uses as much as digits as its factorization.

191006087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44688.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 191006087 is about 13820.4951792618. The cubic root of 191006087 is about 575.9026397541.

The spelling of 191006087 in words is "one hundred ninety-one million, six thousand, eighty-seven".