21111211112212 has 36 divisors (see below), whose sum is σ = 40297128820956. Its totient is φ = 9672514425600.

The previous prime is 21111211112191. The next prime is 21111211112219. The reversal of 21111211112212 is 21221111211112.

It can be written as a sum of positive squares in 6 ways, for example, as 933183048196 + 20178028064016 = 966014^2 + 4491996^2 .

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21111211112212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111211112219) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 113884039 + ... + 114069262.

It is an arithmetic number, because the mean of its divisors is an integer number (1119364689471).

Almost surely, 2^{21111211112212} is an apocalyptic number.

It is an amenable number.

21111211112212 is a deficient number, since it is larger than the sum of its proper divisors (19185917708744).

21111211112212 is a wasteful number, since it uses less digits than its factorization.

21111211112212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227953468 (or 227953453 counting only the distinct ones).

The product of its digits is 32, while the sum is 19.

Adding to 21111211112212 its reverse (21221111211112), we get a palindrome (42332322323324).

It can be divided in two parts, 21111211112 and 212, that multiplied together give a palindrome (4475576755744).

The spelling of 21111211112212 in words is "twenty-one trillion, one hundred eleven billion, two hundred eleven million, one hundred twelve thousand, two hundred twelve".