21121212100211 has 4 divisors (see below), whose sum is σ = 21121296482424. Its totient is φ = 21121127718000.

The previous prime is 21121212100207. The next prime is 21121212100217. The reversal of 21121212100211 is 11200121212112.

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

It is a cyclic number.

It is not a de Polignac number, because 21121212100211 - 2² = 21121212100207 is a prime.

It is a super-2 number, since 2×21121212100211² (a number of 27 digits) contains 22 as substring.

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 21121212100211.

It is not an unprimeable number, because it can be changed into a prime (21121212100217) 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, 41814530 + ... + 42316631.

It is an arithmetic number, because the mean of its divisors is an integer number (5280324120606).

Almost surely, 2^{21121212100211} is an apocalyptic number.

21121212100211 is a deficient number, since it is larger than the sum of its proper divisors (84382213).

21121212100211 is an equidigital number, since it uses as much as digits as its factorization.

21121212100211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84382212.

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

Adding to 21121212100211 its reverse (11200121212112), we get a palindrome (32321333312323).

The spelling of 21121212100211 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, one hundred thousand, two hundred eleven".