21120212021220 has 384 divisors, whose sum is σ = 74536829337600. Its totient is φ = 4921840848384.

The previous prime is 21120212021219. The next prime is 21120212021257. The reversal of 21120212021220 is 2212021202112.

It is a happy number.

21120212021220 is a `hidden beast` number, since 211 + 2 + 0 + 212 + 0 + 21 + 220 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21120212021193 and 21120212021202.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 198282817 + ... + 198389303.

It is an arithmetic number, because the mean of its divisors is an integer number (194106326400).

Almost surely, 2^{21120212021220} is an apocalyptic number.

21120212021220 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 21120212021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37268414668800).

21120212021220 is an abundant number, since it is smaller than the sum of its proper divisors (53416617316380).

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

21120212021220 is a wasteful number, since it uses less digits than its factorization.

21120212021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108024 (or 108016 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21120212021220 its reverse (2212021202112), we get a palindrome (23332233223332).

The spelling of 21120212021220 in words is "twenty-one trillion, one hundred twenty billion, two hundred twelve million, twenty-one thousand, two hundred twenty".