21212110011 has 4 divisors (see below), whose sum is σ = 28282813352. Its totient is φ = 14141406672.

The previous prime is 21212109967. The next prime is 21212110013. The reversal of 21212110011 is 11001121212.

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

It is a de Polignac number, because none of the positive numbers 2^k-21212110011 is a prime.

It is a super-3 number, since 3×21212110011³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212110013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3535351666 + ... + 3535351671.

It is an arithmetic number, because the mean of its divisors is an integer number (7070703338).

Almost surely, 2^21212110011 is an apocalyptic number.

21212110011 is a deficient number, since it is larger than the sum of its proper divisors (7070703341).

21212110011 is an equidigital number, since it uses as much as digits as its factorization.

21212110011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7070703340.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21212110011 its reverse (11001121212), we get a palindrome (32213231223).

It can be divided in two parts, 21212 and 110011, that multiplied together give a palindrome (2333553332).

The spelling of 21212110011 in words is "twenty-one billion, two hundred twelve million, one hundred ten thousand, eleven".