213221221 has 8 divisors (see below), whose sum is σ = 217756800. Its totient is φ = 208716480.

The previous prime is 213221209. The next prime is 213221243. The reversal of 213221221 is 122122312.

It is a happy number.

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 213221221 - 2¹³ = 213213029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213221195 and 213221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213221251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6541 + ... + 21661.

It is an arithmetic number, because the mean of its divisors is an integer number (27219600).

Almost surely, 2^213221221 is an apocalyptic number.

It is an amenable number.

213221221 is a deficient number, since it is larger than the sum of its proper divisors (4535579).

213221221 is a wasteful number, since it uses less digits than its factorization.

213221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15419.

The product of its digits is 96, while the sum is 16.

The square root of 213221221 is about 14602.0964590705. The cubic root of 213221221 is about 597.4159435451.

Adding to 213221221 its reverse (122122312), we get a palindrome (335343533).

The spelling of 213221221 in words is "two hundred thirteen million, two hundred twenty-one thousand, two hundred twenty-one".