491803 has 4 divisors (see below), whose sum is σ = 529648. Its totient is φ = 453960.

The previous prime is 491797. The next prime is 491819. The reversal of 491803 is 308194.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 308194 = 2 ⋅154097.

It is not a de Polignac number, because 491803 - 2¹³ = 483611 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (491833) 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, 18903 + ... + 18928.

It is an arithmetic number, because the mean of its divisors is an integer number (132412).

2⁴⁹¹⁸⁰³ is an apocalyptic number.

491803 is a deficient number, since it is larger than the sum of its proper divisors (37845).

491803 is a wasteful number, since it uses less digits than its factorization.

491803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37844.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 491803 is about 701.2866746203. The cubic root of 491803 is about 78.9339296969.

Adding to 491803 its reverse (308194), we get a palindrome (799997).

The spelling of 491803 in words is "four hundred ninety-one thousand, eight hundred three".