2111212110221 has 4 divisors (see below), whose sum is σ = 2116639391100. Its totient is φ = 2105784829344.

The previous prime is 2111212110211. The next prime is 2111212110239. The reversal of 2111212110221 is 1220112121112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 644664468100 + 1466547642121 = 802910^2 + 1211011^2 .

It is a cyclic number.

It is not a de Polignac number, because 2111212110221 - 2³⁰ = 2110138368397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2111212110221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111212110211) 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, 2713639856 + ... + 2713640633.

It is an arithmetic number, because the mean of its divisors is an integer number (529159847775).

Almost surely, 2^{2111212110221} is an apocalyptic number.

It is an amenable number.

2111212110221 is a deficient number, since it is larger than the sum of its proper divisors (5427280879).

2111212110221 is an equidigital number, since it uses as much as digits as its factorization.

2111212110221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5427280878.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 2111212110221 its reverse (1220112121112), we get a palindrome (3331324231333).

The spelling of 2111212110221 in words is "two trillion, one hundred eleven billion, two hundred twelve million, one hundred ten thousand, two hundred twenty-one".