2100111211221 has 4 divisors (see below), whose sum is σ = 2800148281632. Its totient is φ = 1400074140812.

The previous prime is 2100111211207. The next prime is 2100111211229. The reversal of 2100111211221 is 1221121110012.

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 2100111211221 - 2⁵ = 2100111211189 is a prime.

It is a super-2 number, since 2×2100111211221² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2100111211221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100111211229) 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, 350018535201 + ... + 350018535206.

It is an arithmetic number, because the mean of its divisors is an integer number (700037070408).

Almost surely, 2^{2100111211221} is an apocalyptic number.

It is an amenable number.

2100111211221 is a deficient number, since it is larger than the sum of its proper divisors (700037070411).

2100111211221 is an equidigital number, since it uses as much as digits as its factorization.

2100111211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700037070410.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 2100111211221 its reverse (1221121110012), we get a palindrome (3321232321233).

The spelling of 2100111211221 in words is "two trillion, one hundred billion, one hundred eleven million, two hundred eleven thousand, two hundred twenty-one".