21221100112120 has 128 divisors (see below), whose sum is σ = 49965871818240. Its totient is φ = 8102171934720.

The previous prime is 21221100112109. The next prime is 21221100112127. The reversal of 21221100112120 is 2121100112212.

It is a junction number, because it is equal to n+sod(n) for n = 21221100112094 and 21221100112103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221100112127) 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, 34940964 + ... + 35543116.

It is an arithmetic number, because the mean of its divisors is an integer number (390358373580).

Almost surely, 2^{21221100112120} is an apocalyptic number.

21221100112120 is a gapful number since it is divisible by the number (20) 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 21221100112120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24982935909120).

21221100112120 is an abundant number, since it is smaller than the sum of its proper divisors (28744771706120).

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

21221100112120 is a wasteful number, since it uses less digits than its factorization.

21221100112120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602585 (or 602581 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21221100112120 its reverse (2121100112212), we get a palindrome (23342200224332).

The spelling of 21221100112120 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred million, one hundred twelve thousand, one hundred twenty".