21002002101220 has 72 divisors (see below), whose sum is σ = 53535538332864. Its totient is φ = 6887613104064.

The previous prime is 21002002101187. The next prime is 21002002101263. The reversal of 21002002101220 is 2210120020012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21002002101220.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 465860382 + ... + 465905461.

It is an arithmetic number, because the mean of its divisors is an integer number (743549143512).

Almost surely, 2^{21002002101220} is an apocalyptic number.

21002002101220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002002101220 is an abundant number, since it is smaller than the sum of its proper divisors (32533536231644).

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

21002002101220 is a wasteful number, since it uses less digits than its factorization.

21002002101220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 931765889 (or 931765880 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21002002101220 its reverse (2210120020012), we get a palindrome (23212122121232).

The spelling of 21002002101220 in words is "twenty-one trillion, two billion, two million, one hundred one thousand, two hundred twenty".