211221212020121 has 4 divisors (see below), whose sum is σ = 211225614619572. Its totient is φ = 211216809420672.

The previous prime is 211221212020103. The next prime is 211221212020123. The reversal of 211221212020121 is 121020212122112.

211221212020121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 147196585651600 + 64024626368521 = 12132460^2 + 8001539^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221212020121 - 2⁶ = 211221212020057 is a prime.

It is a super-2 number, since 2×211221212020121² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211221212020093 and 211221212020102.

It is not an unprimeable number, because it can be changed into a prime (211221212020123) 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, 2201227760 + ... + 2201323713.

It is an arithmetic number, because the mean of its divisors is an integer number (52806403654893).

Almost surely, 2^{211221212020121} is an apocalyptic number.

It is an amenable number.

211221212020121 is a deficient number, since it is larger than the sum of its proper divisors (4402599451).

211221212020121 is an equidigital number, since it uses as much as digits as its factorization.

211221212020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4402599450.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 211221212020121 its reverse (121020212122112), we get a palindrome (332241424142233).

The spelling of 211221212020121 in words is "two hundred eleven trillion, two hundred twenty-one billion, two hundred twelve million, twenty thousand, one hundred twenty-one".