21120121100120 has 128 divisors (see below), whose sum is σ = 54492446736000. Its totient is φ = 7216717787136.

The previous prime is 21120121100069. The next prime is 21120121100123. The reversal of 21120121100120 is 2100112102112.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a junction number, because it is equal to n+sod(n) for n = 21120121100095 and 21120121100104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120121100123) 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, 553602806 + ... + 553640954.

It is an arithmetic number, because the mean of its divisors is an integer number (425722240125).

Almost surely, 2^{21120121100120} is an apocalyptic number.

21120121100120 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 21120121100120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27246223368000).

21120121100120 is an abundant number, since it is smaller than the sum of its proper divisors (33372325635880).

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

21120121100120 is a wasteful number, since it uses less digits than its factorization.

21120121100120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44797 (or 44793 counting only the distinct ones).

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

Adding to 21120121100120 its reverse (2100112102112), we get a palindrome (23220233202232).

The spelling of 21120121100120 in words is "twenty-one trillion, one hundred twenty billion, one hundred twenty-one million, one hundred thousand, one hundred twenty".