21212043322420 has 72 divisors (see below), whose sum is σ = 47359618469856. Its totient is φ = 7978980205056.

The previous prime is 21212043322417. The next prime is 21212043322429. The reversal of 21212043322420 is 2422334021212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212043322429) 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 23 ways as a sum of consecutive naturals, for example, 5314987 + ... + 8406733.

It is an arithmetic number, because the mean of its divisors is an integer number (657772478748).

Almost surely, 2^{21212043322420} is an apocalyptic number.

21212043322420 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 21212043322420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23679809234928).

21212043322420 is an abundant number, since it is smaller than the sum of its proper divisors (26147575147436).

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

21212043322420 is a wasteful number, since it uses less digits than its factorization.

21212043322420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3092977 (or 3092958 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21212043322420 its reverse (2422334021212), we get a palindrome (23634377343632).

The spelling of 21212043322420 in words is "twenty-one trillion, two hundred twelve billion, forty-three million, three hundred twenty-two thousand, four hundred twenty".