21001021102220 has 48 divisors (see below), whose sum is σ = 45528569990400. Its totient is φ = 8128753263360.

The previous prime is 21001021102157. The next prime is 21001021102247. The reversal of 21001021102220 is 2220112010012.

It is a junction number, because it is equal to n+sod(n) for n = 21001021102195 and 21001021102204.

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, 6108926 + ... + 8906234.

It is an arithmetic number, because the mean of its divisors is an integer number (948511874800).

Almost surely, 2^{21001021102220} is an apocalyptic number.

21001021102220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001021102220 is an abundant number, since it is smaller than the sum of its proper divisors (24527548888180).

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

21001021102220 is a wasteful number, since it uses less digits than its factorization.

21001021102220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2809458 (or 2809456 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21001021102220 its reverse (2220112010012), we get a palindrome (23221133112232).

The spelling of 21001021102220 in words is "twenty-one trillion, one billion, twenty-one million, one hundred two thousand, two hundred twenty".