21001202221120 has 168 divisors, whose sum is σ = 55182606339672. Its totient is φ = 7607082024960.

The previous prime is 21001202221081. The next prime is 21001202221123. The reversal of 21001202221120 is 2112220210012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2802650988544 + 18198551232576 = 1674112^2 + 4265976^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 21001202221094 and 21001202221103.

It is not an unprimeable number, because it can be changed into a prime (21001202221123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8895814 + ... + 11006266.

It is an arithmetic number, because the mean of its divisors is an integer number (328467894879).

Almost surely, 2^{21001202221120} is an apocalyptic number.

21001202221120 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 21001202221120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27591303169836).

21001202221120 is an abundant number, since it is smaller than the sum of its proper divisors (34181404118552).

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

21001202221120 is a wasteful number, since it uses less digits than its factorization.

21001202221120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2110749 (or 2110728 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21001202221120 its reverse (2112220210012), we get a palindrome (23113422431132).

The spelling of 21001202221120 in words is "twenty-one trillion, one billion, two hundred two million, two hundred twenty-one thousand, one hundred twenty".