213021221 has 8 divisors (see below), whose sum is σ = 245864064. Its totient is φ = 180781200.

The previous prime is 213021191. The next prime is 213021223. The reversal of 213021221 is 122120312.

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 213021221 - 2⁶ = 213021157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 213021196 and 213021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213021223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149945 + ... + 151358.

It is an arithmetic number, because the mean of its divisors is an integer number (30733008).

Almost surely, 2^213021221 is an apocalyptic number.

It is an amenable number.

213021221 is a deficient number, since it is larger than the sum of its proper divisors (32842843).

213021221 is a wasteful number, since it uses less digits than its factorization.

213021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301411.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 213021221 is about 14595.2465206998. The cubic root of 213021221 is about 597.2290944660.

Adding to 213021221 its reverse (122120312), we get a palindrome (335141533).

Subtracting from 213021221 its reverse (122120312), we obtain a palindrome (90900909).

The spelling of 213021221 in words is "two hundred thirteen million, twenty-one thousand, two hundred twenty-one".