1220210221 has 4 divisors (see below), whose sum is σ = 1235656000. Its totient is φ = 1204764444.

The previous prime is 1220210209. The next prime is 1220210227. The reversal of 1220210221 is 1220120221.

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 1220210221 - 2²¹ = 1218113069 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 (1220210227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7722771 + ... + 7722928.

It is an arithmetic number, because the mean of its divisors is an integer number (308914000).

Almost surely, 2^1220210221 is an apocalyptic number.

It is an amenable number.

1220210221 is a deficient number, since it is larger than the sum of its proper divisors (15445779).

1220210221 is an equidigital number, since it uses as much as digits as its factorization.

1220210221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15445778.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1220210221 is about 34931.5075683830. The cubic root of 1220210221 is about 1068.5911002275.

Adding to 1220210221 its reverse (1220120221), we get a palindrome (2440330442).

Subtracting from 1220210221 its reverse (1220120221), we obtain a square (90000 = 300²).

The spelling of 1220210221 in words is "one billion, two hundred twenty million, two hundred ten thousand, two hundred twenty-one".