21000100220 has 48 divisors (see below), whose sum is σ = 48161137248. Its totient is φ = 7628175360.

The previous prime is 21000100213. The next prime is 21000100237. The reversal of 21000100220 is 2200100012.

It is a junction number, because it is equal to n+sod(n) for n = 21000100198 and 21000100207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155204 + ... + 257076.

It is an arithmetic number, because the mean of its divisors is an integer number (1003357026).

Almost surely, 2^21000100220 is an apocalyptic number.

21000100220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000100220 is an abundant number, since it is smaller than the sum of its proper divisors (27161037028).

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

21000100220 is a wasteful number, since it uses less digits than its factorization.

21000100220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102830 (or 102828 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 21000100220 its reverse (2200100012), we get a palindrome (23200200232).

The spelling of 21000100220 in words is "twenty-one billion, one hundred thousand, two hundred twenty".