21021220221120 has 504 divisors, whose sum is σ = 84698158682592. Its totient is φ = 4687651307520.

The previous prime is 21021220221097. The next prime is 21021220221139. The reversal of 21021220221120 is 2112202212012.

It is a happy number.

21021220221120 is a `hidden beast` number, since 2 + 102 + 1 + 220 + 221 + 120 = 666.

It is a tau number, because it is divible by the number of its divisors (504).

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 = 21021220221093 and 21021220221102.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 33578812 + ... + 34199108.

It is an arithmetic number, because the mean of its divisors is an integer number (168051902148).

Almost surely, 2^{21021220221120} is an apocalyptic number.

21021220221120 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 21021220221120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42349079341296).

21021220221120 is an abundant number, since it is smaller than the sum of its proper divisors (63676938461472).

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

21021220221120 is a wasteful number, since it uses less digits than its factorization.

21021220221120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620409 (or 620355 counting only the distinct ones).

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

Adding to 21021220221120 its reverse (2112202212012), we get a palindrome (23133422433132).

The spelling of 21021220221120 in words is "twenty-one trillion, twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred twenty".