221231213 has 8 divisors (see below), whose sum is σ = 253211328. Its totient is φ = 189345024.

The previous prime is 221231207. The next prime is 221231233. The reversal of 221231213 is 312132122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221231213 - 2¹⁰ = 221230189 is a prime.

It is a super-3 number, since 3×221231213³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221231191 and 221231200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221231233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18356 + ... + 27917.

It is an arithmetic number, because the mean of its divisors is an integer number (31651416).

Almost surely, 2^221231213 is an apocalyptic number.

It is an amenable number.

221231213 is a deficient number, since it is larger than the sum of its proper divisors (31980115).

221231213 is an equidigital number, since it uses as much as digits as its factorization.

221231213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46963.

The product of its digits is 144, while the sum is 17.

The square root of 221231213 is about 14873.8432491404. The cubic root of 221231213 is about 604.8051308742.

Adding to 221231213 its reverse (312132122), we get a palindrome (533363335).

Subtracting 221231213 from its reverse (312132122), we obtain a palindrome (90900909).

The spelling of 221231213 in words is "two hundred twenty-one million, two hundred thirty-one thousand, two hundred thirteen".