21220110120 has 128 divisors (see below), whose sum is σ = 70399290240. Its totient is φ = 5073776640.

The previous prime is 21220110113. The next prime is 21220110137. The reversal of 21220110120 is 2101102212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 21220110096 and 21220110105.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13749 + ... + 206468.

It is an arithmetic number, because the mean of its divisors is an integer number (549994455).

Almost surely, 2^21220110120 is an apocalyptic number.

21220110120 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 21220110120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35199645120).

21220110120 is an abundant number, since it is smaller than the sum of its proper divisors (49179180120).

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

21220110120 is a wasteful number, since it uses less digits than its factorization.

21220110120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220315 (or 220311 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21220110120 its reverse (2101102212), we get a palindrome (23321212332).

The spelling of 21220110120 in words is "twenty-one billion, two hundred twenty million, one hundred ten thousand, one hundred twenty".