20021220216 has 192 divisors, whose sum is σ = 57476109600. Its totient is φ = 6286285824.

The previous prime is 20021220199. The next prime is 20021220217. The reversal of 20021220216 is 61202212002.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021220217) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25120330 + ... + 25121126.

Almost surely, 2^20021220216 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 20021220216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28738054800).

20021220216 is an abundant number, since it is smaller than the sum of its proper divisors (37454889384).

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

20021220216 is a wasteful number, since it uses less digits than its factorization.

20021220216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1118 (or 1111 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 20021220216 its reverse (61202212002), we get a palindrome (81223432218).

The spelling of 20021220216 in words is "twenty billion, twenty-one million, two hundred twenty thousand, two hundred sixteen".