2121210110221 has 4 divisors (see below), whose sum is σ = 2121213724000. Its totient is φ = 2121206496444.

The previous prime is 2121210110209. The next prime is 2121210110233. The reversal of 2121210110221 is 1220110121212.

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 an interprime number because it is at equal distance from previous prime (2121210110209) and next prime (2121210110233).

It is a cyclic number.

It is not a de Polignac number, because 2121210110221 - 2¹⁵ = 2121210077453 is a prime.

It is a super-3 number, since 3×2121210110221³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121210110195 and 2121210110204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121210110821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 700671 + ... + 2175628.

It is an arithmetic number, because the mean of its divisors is an integer number (530303431000).

Almost surely, 2^{2121210110221} is an apocalyptic number.

It is an amenable number.

2121210110221 is a deficient number, since it is larger than the sum of its proper divisors (3613779).

2121210110221 is an equidigital number, since it uses as much as digits as its factorization.

2121210110221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3613778.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 2121210110221 its reverse (1220110121212), we get a palindrome (3341320231433).

The spelling of 2121210110221 in words is "two trillion, one hundred twenty-one billion, two hundred ten million, one hundred ten thousand, two hundred twenty-one".