21100200220 has 144 divisors (see below), whose sum is σ = 50667611904. Its totient is φ = 7367500800.

The previous prime is 21100200217. The next prime is 21100200223. The reversal of 21100200220 is 2200200112.

It is an interprime number because it is at equal distance from previous prime (21100200217) and next prime (21100200223).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21100200197 and 21100200206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100200223) 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, 10276714 + ... + 10278766.

It is an arithmetic number, because the mean of its divisors is an integer number (351858416).

Almost surely, 2^21100200220 is an apocalyptic number.

21100200220 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 21100200220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25333805952).

21100200220 is an abundant number, since it is smaller than the sum of its proper divisors (29567411684).

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

21100200220 is a wasteful number, since it uses less digits than its factorization.

21100200220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2252 (or 2239 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21100200220 its reverse (2200200112), we get a palindrome (23300400332).

The spelling of 21100200220 in words is "twenty-one billion, one hundred million, two hundred thousand, two hundred twenty".