21212103121211 has 4 divisors (see below), whose sum is σ = 21212114163552. Its totient is φ = 21212092078872.

The previous prime is 21212103121193. The next prime is 21212103121309. The reversal of 21212103121211 is 11212130121212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21212103121211 - 2²⁶ = 21212036012347 is a prime.

It is a super-3 number, since 3×21212103121211³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212103129211) 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, 1806716 + ... + 6759321.

It is an arithmetic number, because the mean of its divisors is an integer number (5303028540888).

Almost surely, 2^{21212103121211} is an apocalyptic number.

21212103121211 is a deficient number, since it is larger than the sum of its proper divisors (11042341).

21212103121211 is an equidigital number, since it uses as much as digits as its factorization.

21212103121211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11042340.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 21212103121211 its reverse (11212130121212), we get a palindrome (32424233242423).

The spelling of 21212103121211 in words is "twenty-one trillion, two hundred twelve billion, one hundred three million, one hundred twenty-one thousand, two hundred eleven".