420823 has 4 divisors (see below), whose sum is σ = 453208. Its totient is φ = 388440.

The previous prime is 420811. The next prime is 420851. The reversal of 420823 is 328024.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-420823 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 420823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (420803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16173 + ... + 16198.

It is an arithmetic number, because the mean of its divisors is an integer number (113302).

2⁴²⁰⁸²³ is an apocalyptic number.

420823 is a deficient number, since it is larger than the sum of its proper divisors (32385).

420823 is a wasteful number, since it uses less digits than its factorization.

420823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32384.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 420823 is about 648.7087173763. The cubic root of 420823 is about 74.9376073691.

Adding to 420823 its reverse (328024), we get a palindrome (748847).

The spelling of 420823 in words is "four hundred twenty thousand, eight hundred twenty-three".