21211111212112 has 20 divisors (see below), whose sum is σ = 41372343602100. Its totient is φ = 10534377379328.

The previous prime is 21211111212107. The next prime is 21211111212133. The reversal of 21211111212112 is 21121211111212.

It can be written as a sum of positive squares in 2 ways, for example, as 10719757002816 + 10491354209296 = 3274104^2 + 3239036^2 .

It is a super-2 number, since 2×21211111212112² (a number of 27 digits) contains 22 as substring.

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 21211111212112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4448636713 + ... + 4448641480.

It is an arithmetic number, because the mean of its divisors is an integer number (2068617180105).

Almost surely, 2^{21211111212112} is an apocalyptic number.

It is an amenable number.

21211111212112 is a deficient number, since it is larger than the sum of its proper divisors (20161232389988).

21211111212112 is a wasteful number, since it uses less digits than its factorization.

21211111212112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8897278350 (or 8897278344 counting only the distinct ones).

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

Adding to 21211111212112 its reverse (21121211111212), we get a palindrome (42332322323324).

The spelling of 21211111212112 in words is "twenty-one trillion, two hundred eleven billion, one hundred eleven million, two hundred twelve thousand, one hundred twelve".