21201212101110 has 32 divisors (see below), whose sum is σ = 50884727074560. Its totient is φ = 5653454556768.

The previous prime is 21201212101021. The next prime is 21201212101163. The reversal of 21201212101110 is 1110121210212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21201212101110.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 11770642 + ... + 13451781.

It is an arithmetic number, because the mean of its divisors is an integer number (1590147721080).

Almost surely, 2^{21201212101110} is an apocalyptic number.

21201212101110 is an abundant number, since it is smaller than the sum of its proper divisors (29683514973450).

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

21201212101110 is a wasteful number, since it uses less digits than its factorization.

21201212101110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25250452.

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

Adding to 21201212101110 its reverse (1110121210212), we get a palindrome (22311333311322).

The spelling of 21201212101110 in words is "twenty-one trillion, two hundred one billion, two hundred twelve million, one hundred one thousand, one hundred ten".