21002000220 has 192 divisors, whose sum is σ = 66572513280. Its totient is φ = 5495616000.

The previous prime is 21002000207. The next prime is 21002000221. The reversal of 21002000220 is 2200020012.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002000221) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8932045 + ... + 8934395.

It is an arithmetic number, because the mean of its divisors is an integer number (346731840).

Almost surely, 2^21002000220 is an apocalyptic number.

21002000220 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 21002000220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33286256640).

21002000220 is an abundant number, since it is smaller than the sum of its proper divisors (45570513060).

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

21002000220 is a wasteful number, since it uses less digits than its factorization.

21002000220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2673 (or 2665 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

Adding to 21002000220 its reverse (2200020012), we get a palindrome (23202020232).

The spelling of 21002000220 in words is "twenty-one billion, two million, two hundred twenty", and thus it is an aban number.