21202220221220 has 24 divisors (see below), whose sum is σ = 44640914863104. Its totient is φ = 8458744774496.

The previous prime is 21202220221213. The next prime is 21202220221223. The reversal of 21202220221220 is 2212202220212.

It is a super-2 number, since 2×21202220221220² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21202220221192 and 21202220221201.

It is not an unprimeable number, because it can be changed into a prime (21202220221223) 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 7 ways as a sum of consecutive naturals, for example, 1383949274 + ... + 1383964593.

It is an arithmetic number, because the mean of its divisors is an integer number (1860038119296).

Almost surely, 2^{21202220221220} is an apocalyptic number.

21202220221220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202220221220 is an abundant number, since it is smaller than the sum of its proper divisors (23438694641884).

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

21202220221220 is a wasteful number, since it uses less digits than its factorization.

21202220221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2767914259 (or 2767914257 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 21202220221220 its reverse (2212202220212), we get a palindrome (23414422441432).

The spelling of 21202220221220 in words is "twenty-one trillion, two hundred two billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twenty".