201210221 has 4 divisors (see below), whose sum is σ = 203471100. Its totient is φ = 198949344.

The previous prime is 201210211. The next prime is 201210223. The reversal of 201210221 is 122012102.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 65836996 + 135373225 = 8114^2 + 11635^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201210221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201210223) 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, 1130306 + ... + 1130483.

It is an arithmetic number, because the mean of its divisors is an integer number (50867775).

Almost surely, 2^201210221 is an apocalyptic number.

It is an amenable number.

201210221 is a deficient number, since it is larger than the sum of its proper divisors (2260879).

201210221 is an equidigital number, since it uses as much as digits as its factorization.

201210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2260878.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 201210221 is about 14184.8588642961. The cubic root of 201210221 is about 585.9807456001.

Adding to 201210221 its reverse (122012102), we get a palindrome (323222323).

The spelling of 201210221 in words is "two hundred one million, two hundred ten thousand, two hundred twenty-one".