21121220102220 has 144 divisors (see below), whose sum is σ = 73222215026688. Its totient is φ = 4827576551040.

The previous prime is 21121220102207. The next prime is 21121220102221. The reversal of 21121220102220 is 2220102212112.

It is a happy number.

21121220102220 is a `hidden beast` number, since 2 + 1 + 121 + 220 + 102 + 220 = 666.

It is a super-2 number, since 2×21121220102220² (a number of 27 digits) contains 22 as substring.

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 = 21121220102193 and 21121220102202.

It is not an unprimeable number, because it can be changed into a prime (21121220102221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50806605 + ... + 51220635.

It is an arithmetic number, because the mean of its divisors is an integer number (508487604352).

Almost surely, 2^{21121220102220} is an apocalyptic number.

21121220102220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121220102220 is an abundant number, since it is smaller than the sum of its proper divisors (52100994924468).

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

21121220102220 is a wasteful number, since it uses less digits than its factorization.

21121220102220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454540 (or 454535 counting only the distinct ones).

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

Adding to 21121220102220 its reverse (2220102212112), we get a palindrome (23341322314332).

The spelling of 21121220102220 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty million, one hundred two thousand, two hundred twenty".