2101020221 has 4 divisors (see below), whose sum is σ = 2120656032. Its totient is φ = 2081384412.

The previous prime is 2101020203. The next prime is 2101020379. The reversal of 2101020221 is 1220201012.

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 2101020221 - 2²⁶ = 2033911357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101080221) 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, 9817745 + ... + 9817958.

It is an arithmetic number, because the mean of its divisors is an integer number (530164008).

Almost surely, 2^2101020221 is an apocalyptic number.

It is an amenable number.

2101020221 is a deficient number, since it is larger than the sum of its proper divisors (19635811).

2101020221 is a wasteful number, since it uses less digits than its factorization.

2101020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19635810.

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

The square root of 2101020221 is about 45836.8871216185. The cubic root of 2101020221 is about 1280.7865082007.

Adding to 2101020221 its reverse (1220201012), we get a palindrome (3321221233).

The spelling of 2101020221 in words is "two billion, one hundred one million, twenty thousand, two hundred twenty-one".