491903 has 4 divisors (see below), whose sum is σ = 497520. Its totient is φ = 486288.

The previous prime is 491899. The next prime is 491923. The reversal of 491903 is 309194.

It is a happy number.

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 491903 - 2² = 491899 is a prime.

It is a super-2 number, since 2×491903² = 483937122818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491923) 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, 2675 + ... + 2852.

It is an arithmetic number, because the mean of its divisors is an integer number (124380).

2⁴⁹¹⁹⁰³ is an apocalyptic number.

491903 is a deficient number, since it is larger than the sum of its proper divisors (5617).

491903 is an equidigital number, since it uses as much as digits as its factorization.

491903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5616.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 491903 is about 701.3579685154. The cubic root of 491903 is about 78.9392793038.

The spelling of 491903 in words is "four hundred ninety-one thousand, nine hundred three".