423 has 6 divisors (see below), whose sum is σ = 624. Its totient is φ = 276.

The previous prime is 421. The next prime is 431. The reversal of 423 is 324.

It is not a de Polignac number, because 423 - 2¹ = 421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 47 = 423 / (4 + 2 + 3).

It is a plaindrome in base 11, base 13 and base 14.

It is a nialpdrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15 + ... + 32.

It is an arithmetic number, because the mean of its divisors is an integer number (104).

423 is a deficient number, since it is larger than the sum of its proper divisors (201).

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

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

The sum of its prime factors is 53 (or 50 counting only the distinct ones).

The product of its digits is 24, while the sum is 9.

The square root of 423 is about 20.5669638012. The cubic root of 423 is about 7.5066607495.

Adding to 423 its reverse (324), we get a palindrome (747).

Subtracting from 423 its reverse (324), we obtain a palindrome (99).

It can be divided in two parts, 42 and 3, that added together give a triangular number (45 = T₉).

The spelling of 423 in words is "four hundred twenty-three", and thus it is an aban number and an iban number.