221010221 has 4 divisors (see below), whose sum is σ = 221730432. Its totient is φ = 220290012.

The previous prime is 221010187. The next prime is 221010241. The reversal of 221010221 is 122010122.

It is a happy number.

221010221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221010221 - 2¹⁴ = 220993837 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 (221010241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 359645 + ... + 360258.

It is an arithmetic number, because the mean of its divisors is an integer number (55432608).

Almost surely, 2^221010221 is an apocalyptic number.

It is an amenable number.

221010221 is a deficient number, since it is larger than the sum of its proper divisors (720211).

221010221 is an equidigital number, since it uses as much as digits as its factorization.

221010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720210.

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

The square root of 221010221 is about 14866.4125127752. The cubic root of 221010221 is about 604.6036800593.

Adding to 221010221 its reverse (122010122), we get a palindrome (343020343).

Subtracting from 221010221 its reverse (122010122), we obtain a palindrome (99000099).

The spelling of 221010221 in words is "two hundred twenty-one million, ten thousand, two hundred twenty-one".