491009 has 8 divisors (see below), whose sum is σ = 519168. Its totient is φ = 463680.

The previous prime is 491003. The next prime is 491039. The reversal of 491009 is 900194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 491009 - 2⁴ = 490993 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 (491003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1289 + ... + 1625.

It is an arithmetic number, because the mean of its divisors is an integer number (64896).

2⁴⁹¹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

491009 is a deficient number, since it is larger than the sum of its proper divisors (28159).

491009 is a wasteful number, since it uses less digits than its factorization.

491009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 491009 is about 700.7203436465. The cubic root of 491009 is about 78.8914280594.

The spelling of 491009 in words is "four hundred ninety-one thousand, nine".