21111212122112 has 56 divisors (see below), whose sum is σ = 48251254064736. Its totient is φ = 9047662313472.

The previous prime is 21111212122081. The next prime is 21111212122151. The reversal of 21111212122112 is 21122121211112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is an insolite number, because it is divisible by the sum (32) and by the product (4096) of the squares of its digits.

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, 184017818 + ... + 184132505.

Almost surely, 2^{21111212122112} is an apocalyptic number.

It is an amenable number.

21111212122112 is an abundant number, since it is smaller than the sum of its proper divisors (27140041942624).

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

21111212122112 is an frugal number, since it uses more digits than its factorization.

21111212122112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368150356 (or 368150332 counting only the distinct ones).

The product of its digits is 64, while the sum is 20.

Adding to 21111212122112 its reverse (21122121211112), we get a palindrome (42233333333224).

The spelling of 21111212122112 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, one hundred twenty-two thousand, one hundred twelve".