21222220221020 has 144 divisors (see below), whose sum is σ = 56435280168960. Its totient is φ = 6560285292288.

The previous prime is 21222220221011. The next prime is 21222220221031. The reversal of 21222220221020 is 2012202222212.

It is a super-2 number, since 2×21222220221020² (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 = 21222220220983 and 21222220221001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9412460 + ... + 11447219.

It is an arithmetic number, because the mean of its divisors is an integer number (391911667840).

Almost surely, 2^{21222220221020} is an apocalyptic number.

21222220221020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222220221020 is an abundant number, since it is smaller than the sum of its proper divisors (35213059947940).

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

21222220221020 is a wasteful number, since it uses less digits than its factorization.

21222220221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20859764 (or 20859749 counting only the distinct ones).

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

Adding to 21222220221020 its reverse (2012202222212), we get a palindrome (23234422443232).

The spelling of 21222220221020 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty million, two hundred twenty-one thousand, twenty".