21120100011220 has 192 divisors, whose sum is σ = 51975883491840. Its totient is φ = 7057954455552.

The previous prime is 21120100011203. The next prime is 21120100011277. The reversal of 21120100011220 is 2211000102112.

It is a self number, because there is not a number n which added to its sum of digits gives 21120100011220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8825782344 + ... + 8825784736.

It is an arithmetic number, because the mean of its divisors is an integer number (270707726520).

Almost surely, 2^{21120100011220} is an apocalyptic number.

21120100011220 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 21120100011220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25987941745920).

21120100011220 is an abundant number, since it is smaller than the sum of its proper divisors (30855783480620).

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

21120100011220 is a wasteful number, since it uses less digits than its factorization.

21120100011220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4914 (or 4912 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21120100011220 its reverse (2211000102112), we get a palindrome (23331100113332).

The spelling of 21120100011220 in words is "twenty-one trillion, one hundred twenty billion, one hundred million, eleven thousand, two hundred twenty".