213243 has 4 divisors (see below), whose sum is σ = 284328. Its totient is φ = 142160.

The previous prime is 213229. The next prime is 213247. The reversal of 213243 is 342312.

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 213243 - 2⁸ = 212987 is a prime.

It is a D-number.

213243 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (213247) 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, 35538 + ... + 35543.

It is an arithmetic number, because the mean of its divisors is an integer number (71082).

2²¹³²⁴³ is an apocalyptic number.

213243 is a deficient number, since it is larger than the sum of its proper divisors (71085).

213243 is an equidigital number, since it uses as much as digits as its factorization.

213243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71084.

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

The square root of 213243 is about 461.7824162958. The cubic root of 213243 is about 59.7436283420.

Adding to 213243 its reverse (342312), we get a palindrome (555555).

The spelling of 213243 in words is "two hundred thirteen thousand, two hundred forty-three".