2101220221 has 4 divisors (see below), whose sum is σ = 2130814944. Its totient is φ = 2071625500.

The previous prime is 2101220183. The next prime is 2101220227. The reversal of 2101220221 is 1220221012.

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 2101220221 - 2¹⁷ = 2101089149 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 (2101220227) 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, 14797255 + ... + 14797396.

It is an arithmetic number, because the mean of its divisors is an integer number (532703736).

Almost surely, 2^2101220221 is an apocalyptic number.

It is an amenable number.

2101220221 is a deficient number, since it is larger than the sum of its proper divisors (29594723).

2101220221 is an equidigital number, since it uses as much as digits as its factorization.

2101220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29594722.

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

The square root of 2101220221 is about 45839.0687187251. The cubic root of 2101220221 is about 1280.8271470566.

Adding to 2101220221 its reverse (1220221012), we get a palindrome (3321441233).

The spelling of 2101220221 in words is "two billion, one hundred one million, two hundred twenty thousand, two hundred twenty-one".