213823 has 4 divisors (see below), whose sum is σ = 219640. Its totient is φ = 208008.

The previous prime is 213821. The next prime is 213827. The reversal of 213823 is 328312.

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 213823 - 2¹ = 213821 is a prime.

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 213823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2853 + ... + 2926.

It is an arithmetic number, because the mean of its divisors is an integer number (54910).

2²¹³⁸²³ is an apocalyptic number.

213823 is a deficient number, since it is larger than the sum of its proper divisors (5817).

213823 is an equidigital number, since it uses as much as digits as its factorization.

213823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5816.

The product of its digits is 288, while the sum is 19.

The square root of 213823 is about 462.4099912415. The cubic root of 213823 is about 59.7977449066.

It can be divided in two parts, 21382 and 3, that multiplied together give a palindrome (64146).

The spelling of 213823 in words is "two hundred thirteen thousand, eight hundred twenty-three".