2100111221 has 4 divisors (see below), whose sum is σ = 2261658252. Its totient is φ = 1938564192.

The previous prime is 2100111203. The next prime is 2100111239. The reversal of 2100111221 is 1221110012.

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

It is an interprime number because it is at equal distance from previous prime (2100111203) and next prime (2100111239).

It can be written as a sum of positive squares in 2 ways, for example, as 859310596 + 1240800625 = 29314^2 + 35225^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100111221 - 2¹⁴ = 2100094837 is a prime.

It is a super-4 number, since 4×2100111221⁴ (a number of 38 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100111521) 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, 80773496 + ... + 80773521.

It is an arithmetic number, because the mean of its divisors is an integer number (565414563).

Almost surely, 2^2100111221 is an apocalyptic number.

It is an amenable number.

2100111221 is a deficient number, since it is larger than the sum of its proper divisors (161547031).

2100111221 is a wasteful number, since it uses less digits than its factorization.

2100111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161547030.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 2100111221 is about 45826.9704540896. The cubic root of 2100111221 is about 1280.6017720956.

Adding to 2100111221 its reverse (1221110012), we get a palindrome (3321221233).

The spelling of 2100111221 in words is "two billion, one hundred million, one hundred eleven thousand, two hundred twenty-one".