243213 has 4 divisors (see below), whose sum is σ = 324288. Its totient is φ = 162140.

The previous prime is 243209. The next prime is 243227. The reversal of 243213 is 312342.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 243213 - 2² = 243209 is a prime.

It is a d-powerful number, because it can be written as 2³ + 4⁸ + 2⁹ + 3² + 1 + 3¹¹ .

It is a D-number.

243213 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 243192 and 243201.

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 243213.

It is not an unprimeable number, because it can be changed into a prime (243203) 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, 40533 + ... + 40538.

It is an arithmetic number, because the mean of its divisors is an integer number (81072).

2²⁴³²¹³ is an apocalyptic number.

It is an amenable number.

243213 is a deficient number, since it is larger than the sum of its proper divisors (81075).

243213 is an equidigital number, since it uses as much as digits as its factorization.

243213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81074.

The product of its digits is 144, while the sum is 15.

The square root of 243213 is about 493.1663005519. The cubic root of 243213 is about 62.4207422004.

Adding to 243213 its reverse (312342), we get a palindrome (555555).

The spelling of 243213 in words is "two hundred forty-three thousand, two hundred thirteen".