21120213131220 has 288 divisors, whose sum is σ = 72853884407808. Its totient is φ = 4548666786048.

The previous prime is 21120213131207. The next prime is 21120213131249. The reversal of 21120213131220 is 2213131202112.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2199669 + ... + 6861411.

It is an arithmetic number, because the mean of its divisors is an integer number (252964876416).

Almost surely, 2^{21120213131220} is an apocalyptic number.

21120213131220 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 21120213131220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36426942203904).

21120213131220 is an abundant number, since it is smaller than the sum of its proper divisors (51733671276588).

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

21120213131220 is a wasteful number, since it uses less digits than its factorization.

21120213131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4661859 (or 4661850 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 21120213131220 its reverse (2213131202112), we get a palindrome (23333344333332).

The spelling of 21120213131220 in words is "twenty-one trillion, one hundred twenty billion, two hundred thirteen million, one hundred thirty-one thousand, two hundred twenty".