21001021021112 has 128 divisors (see below), whose sum is σ = 45798124032000. Its totient is φ = 8927420261760.

The previous prime is 21001021020989. The next prime is 21001021021117. The reversal of 21001021021112 is 21112012010012.

It is a super-2 number, since 2×21001021021112² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001021021117) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 996857603 + ... + 996878669.

It is an arithmetic number, because the mean of its divisors is an integer number (357797844000).

Almost surely, 2^{21001021021112} is an apocalyptic number.

21001021021112 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 21001021021112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22899062016000).

21001021021112 is an abundant number, since it is smaller than the sum of its proper divisors (24797103010888).

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

21001021021112 is a wasteful number, since it uses less digits than its factorization.

21001021021112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28729 (or 28725 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21001021021112 its reverse (21112012010012), we get a palindrome (42113033031124).

The spelling of 21001021021112 in words is "twenty-one trillion, one billion, twenty-one million, twenty-one thousand, one hundred twelve".