213123211 has 4 divisors (see below), whose sum is σ = 243569392. Its totient is φ = 182677032.

The previous prime is 213123199. The next prime is 213123217. The reversal of 213123211 is 112321312.

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 213123211 - 2¹⁵ = 213090443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213123217) 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, 15223080 + ... + 15223093.

It is an arithmetic number, because the mean of its divisors is an integer number (60892348).

Almost surely, 2^213123211 is an apocalyptic number.

213123211 is a deficient number, since it is larger than the sum of its proper divisors (30446181).

213123211 is an equidigital number, since it uses as much as digits as its factorization.

213123211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30446180.

The product of its digits is 72, while the sum is 16.

The square root of 213123211 is about 14598.7400483740. The cubic root of 213123211 is about 597.3243927601.

Adding to 213123211 its reverse (112321312), we get a palindrome (325444523).

The spelling of 213123211 in words is "two hundred thirteen million, one hundred twenty-three thousand, two hundred eleven".