21212101110 has 64 divisors (see below), whose sum is σ = 52311225600. Its totient is φ = 5500916352.

The previous prime is 21212101109. The next prime is 21212101123. The reversal of 21212101110 is 1110121212.

It is a super-3 number, since 3×21212101110³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3125701 + ... + 3132479.

It is an arithmetic number, because the mean of its divisors is an integer number (817362900).

Almost surely, 2^21212101110 is an apocalyptic number.

21212101110 is an abundant number, since it is smaller than the sum of its proper divisors (31099124490).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21212101110 is a wasteful number, since it uses less digits than its factorization.

21212101110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9645.

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

Adding to 21212101110 its reverse (1110121212), we get a palindrome (22322222322).

The spelling of 21212101110 in words is "twenty-one billion, two hundred twelve million, one hundred one thousand, one hundred ten".