21221021002220 has 24 divisors (see below), whose sum is σ = 47992155190224. Its totient is φ = 7835453908416.

The previous prime is 21221021002163. The next prime is 21221021002229. The reversal of 21221021002220 is 2220012012212.

It is a happy number.

21221021002220 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (21221021002229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40809655514 + ... + 40809656033.

It is an arithmetic number, because the mean of its divisors is an integer number (1999673132926).

Almost surely, 2^{21221021002220} is an apocalyptic number.

21221021002220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221021002220 is an abundant number, since it is smaller than the sum of its proper divisors (26771134188004).

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

21221021002220 is a wasteful number, since it uses less digits than its factorization.

21221021002220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81619311569 (or 81619311567 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21221021002220 its reverse (2220012012212), we get a palindrome (23441033014432).

The spelling of 21221021002220 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-one million, two thousand, two hundred twenty".