981191 has 4 divisors (see below), whose sum is σ = 984000. Its totient is φ = 978384.

The previous prime is 981187. The next prime is 981199. The reversal of 981191 is 191189.

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 981191 - 2² = 981187 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 (981199) 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, 791 + ... + 1608.

It is an arithmetic number, because the mean of its divisors is an integer number (246000).

2⁹⁸¹¹⁹¹ is an apocalyptic number.

981191 is a deficient number, since it is larger than the sum of its proper divisors (2809).

981191 is a wasteful number, since it uses less digits than its factorization.

981191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2808.

The product of its digits is 648, while the sum is 29.

The square root of 981191 is about 990.5508568468. The cubic root of 981191 is about 99.3690608636.

The spelling of 981191 in words is "nine hundred eighty-one thousand, one hundred ninety-one".