491091 has 4 divisors (see below), whose sum is σ = 654792. Its totient is φ = 327392.

The previous prime is 491083. The next prime is 491129. The reversal of 491091 is 190194.

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 491091 - 2³ = 491083 is a prime.

It is a D-number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 491091.

It is not an unprimeable number, because it can be changed into a prime (491041) 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, 81846 + ... + 81851.

It is an arithmetic number, because the mean of its divisors is an integer number (163698).

2⁴⁹¹⁰⁹¹ is an apocalyptic number.

491091 is a deficient number, since it is larger than the sum of its proper divisors (163701).

491091 is a wasteful number, since it uses less digits than its factorization.

491091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163700.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 491091 is about 700.7788524206. The cubic root of 491091 is about 78.8958195179.

The spelling of 491091 in words is "four hundred ninety-one thousand, ninety-one".