21121121210112 has 432 divisors, whose sum is σ = 76305685747200. Its totient is φ = 5458428518400.

The previous prime is 21121121210069. The next prime is 21121121210129. The reversal of 21121121210112 is 21101212112112.

It is a happy number.

21121121210112 is a `hidden beast` number, since 211 + 211 + 21 + 210 + 1 + 12 = 666.

It is a super-2 number, since 2×21121121210112² (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 47 ways as a sum of consecutive naturals, for example, 35005062 + ... + 35603322.

Almost surely, 2^{21121121210112} is an apocalyptic number.

21121121210112 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121121210112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38152842873600).

21121121210112 is an abundant number, since it is smaller than the sum of its proper divisors (55184564537088).

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

21121121210112 is a wasteful number, since it uses less digits than its factorization.

21121121210112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 598500 (or 598483 counting only the distinct ones).

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

Adding to 21121121210112 its reverse (21101212112112), we get a palindrome (42222333322224).

The spelling of 21121121210112 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, one hundred twelve".