21212120110011 has 16 divisors (see below), whose sum is σ = 29079562057728. Its totient is φ = 13745591265600.

The previous prime is 21212120110007. The next prime is 21212120110021. The reversal of 21212120110011 is 11001102121212.

It is a happy number.

It is not a de Polignac number, because 21212120110011 - 2² = 21212120110007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212120110021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 318151651 + ... + 318218316.

It is an arithmetic number, because the mean of its divisors is an integer number (1817472628608).

Almost surely, 2^{21212120110011} is an apocalyptic number.

21212120110011 is a deficient number, since it is larger than the sum of its proper divisors (7867441947717).

21212120110011 is a wasteful number, since it uses less digits than its factorization.

21212120110011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636370282.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21212120110011 its reverse (11001102121212), we get a palindrome (32213222231223).

It can be divided in two parts, 212121201 and 10011, that added together give a palindrome (212131212).

The spelling of 21212120110011 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty million, one hundred ten thousand, eleven".