213121212223 has 4 divisors (see below), whose sum is σ = 218077519528. Its totient is φ = 208164904920.

The previous prime is 213121212197. The next prime is 213121212247. The reversal of 213121212223 is 322212121312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213121212223 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 213121212194 and 213121212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213121212523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2478153588 + ... + 2478153673.

It is an arithmetic number, because the mean of its divisors is an integer number (54519379882).

Almost surely, 2^213121212223 is an apocalyptic number.

213121212223 is a deficient number, since it is larger than the sum of its proper divisors (4956307305).

213121212223 is an equidigital number, since it uses as much as digits as its factorization.

213121212223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4956307304.

The product of its digits is 576, while the sum is 22.

Adding to 213121212223 its reverse (322212121312), we get a palindrome (535333333535).

The spelling of 213121212223 in words is "two hundred thirteen billion, one hundred twenty-one million, two hundred twelve thousand, two hundred twenty-three".