21121212101112 has 80 divisors (see below), whose sum is σ = 59162634214200. Its totient is φ = 7039965648960.

The previous prime is 21121212101081. The next prime is 21121212101123. The reversal of 21121212101112 is 21110121212112.

It is a happy number.

It is a super-2 number, since 2×21121212101112² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9483787 + ... + 11497157.

Almost surely, 2^{21121212101112} is an apocalyptic number.

It is an amenable number.

21121212101112 is an abundant number, since it is smaller than the sum of its proper divisors (38041422113088).

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

21121212101112 is a wasteful number, since it uses less digits than its factorization.

21121212101112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2029578 (or 2029565 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21121212101112 its reverse (21110121212112), we get a palindrome (42231333313224).

The spelling of 21121212101112 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, one hundred one thousand, one hundred twelve".