493 has 4 divisors (see below), whose sum is σ = 540. Its totient is φ = 448.

The previous prime is 491. The next prime is 499. The reversal of 493 is 394.

493 is nontrivially palindromic in base 4.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 394 = 2 ⋅197.

It can be written as a sum of positive squares in 2 ways, for example, as 324 + 169 = 18^2 + 13^2 .

It is a cyclic number.

It is not a de Polignac number, because 493 - 2¹ = 491 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13 and base 15.

It is a nialpdrome in base 8.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 493.

It is not an unprimeable number, because it can be changed into a prime (491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3 + ... + 31.

It is an arithmetic number, because the mean of its divisors is an integer number (135).

It is an amenable number.

493 is a deficient number, since it is larger than the sum of its proper divisors (47).

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

With its predecessor (492) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (46).

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

The sum of its prime factors is 46.

The product of its digits is 108, while the sum is 16.

The square root of 493 is about 22.2036033112. The cubic root of 493 is about 7.8997916946.

Subtracting from 493 its reverse (394), we obtain a palindrome (99).

The spelling of 493 in words is "four hundred ninety-three", and thus it is an aban number.