2121100221 has 16 divisors (see below), whose sum is σ = 2945490048. Its totient is φ = 1356465600.

The previous prime is 2121100213. The next prime is 2121100229. The reversal of 2121100221 is 1220011212.

It is an interprime number because it is at equal distance from previous prime (2121100213) and next prime (2121100229).

It is not a de Polignac number, because 2121100221 - 2³ = 2121100213 is a prime.

It is a super-2 number, since 2×2121100221² = 8998132295052497682, which contains 22 as substring.

It is a zygodrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 2121100197 and 2121100206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121100229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126690 + ... + 142451.

It is an arithmetic number, because the mean of its divisors is an integer number (184093128).

Almost surely, 2^2121100221 is an apocalyptic number.

It is an amenable number.

2121100221 is a deficient number, since it is larger than the sum of its proper divisors (824389827).

2121100221 is a wasteful number, since it uses less digits than its factorization.

2121100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269252.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 2121100221 is about 46055.4038197474. The cubic root of 2121100221 is about 1284.8538486395.

Adding to 2121100221 its reverse (1220011212), we get a palindrome (3341111433).

The spelling of 2121100221 in words is "two billion, one hundred twenty-one million, one hundred thousand, two hundred twenty-one".