213220221 has 4 divisors (see below), whose sum is σ = 284293632. Its totient is φ = 142146812.

The previous prime is 213220211. The next prime is 213220229. The reversal of 213220221 is 122022312.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 213220221 - 2¹³ = 213212029 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213220221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213220229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35536701 + ... + 35536706.

It is an arithmetic number, because the mean of its divisors is an integer number (71073408).

Almost surely, 2^213220221 is an apocalyptic number.

It is an amenable number.

213220221 is a deficient number, since it is larger than the sum of its proper divisors (71073411).

213220221 is an equidigital number, since it uses as much as digits as its factorization.

213220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71073410.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 213220221 is about 14602.0622173719. The cubic root of 213220221 is about 597.4150095904.

Adding to 213220221 its reverse (122022312), we get a palindrome (335242533).

The spelling of 213220221 in words is "two hundred thirteen million, two hundred twenty thousand, two hundred twenty-one".