21222232020 has 288 divisors, whose sum is σ = 77139578880. Its totient is φ = 4661902080.

The previous prime is 21222231991. The next prime is 21222232021. The reversal of 21222232020 is 2023222212.

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 = 21222231984 and 21222232002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222232021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 852997 + ... + 877523.

It is an arithmetic number, because the mean of its divisors is an integer number (267845760).

Almost surely, 2^21222232020 is an apocalyptic number.

21222232020 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 21222232020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38569789440).

21222232020 is an abundant number, since it is smaller than the sum of its proper divisors (55917346860).

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

21222232020 is a wasteful number, since it uses less digits than its factorization.

21222232020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24595 (or 24590 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21222232020 its reverse (2023222212), we get a palindrome (23245454232).

The spelling of 21222232020 in words is "twenty-one billion, two hundred twenty-two million, two hundred thirty-two thousand, twenty".