21220033212 has 96 divisors (see below), whose sum is σ = 62930058240. Its totient is φ = 6057478080.

The previous prime is 21220033193. The next prime is 21220033273. The reversal of 21220033212 is 21233002212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 880953 + ... + 904719.

It is an arithmetic number, because the mean of its divisors is an integer number (655521440).

Almost surely, 2^21220033212 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21220033212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31465029120).

21220033212 is an abundant number, since it is smaller than the sum of its proper divisors (41710025028).

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

21220033212 is a wasteful number, since it uses less digits than its factorization.

21220033212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24968 (or 24960 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21220033212 its reverse (21233002212), we get a palindrome (42453035424).

The spelling of 21220033212 in words is "twenty-one billion, two hundred twenty million, thirty-three thousand, two hundred twelve".