21210110111212 has 24 divisors (see below), whose sum is σ = 40554037680912. Its totient is φ = 9626195025600.

The previous prime is 21210110111161. The next prime is 21210110111213. The reversal of 21210110111212 is 21211101101212.

It is not an unprimeable number, because it can be changed into a prime (21210110111213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 369073839 + ... + 369131302.

It is an arithmetic number, because the mean of its divisors is an integer number (1689751570038).

Almost surely, 2^{21210110111212} is an apocalyptic number.

21210110111212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21210110111212 is a deficient number, since it is larger than the sum of its proper divisors (19343927569700).

21210110111212 is a wasteful number, since it uses less digits than its factorization.

21210110111212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738205809 (or 738205807 counting only the distinct ones).

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

Adding to 21210110111212 its reverse (21211101101212), we get a palindrome (42421211212424).

The spelling of 21210110111212 in words is "twenty-one trillion, two hundred ten billion, one hundred ten million, one hundred eleven thousand, two hundred twelve".