21002220120100 has 36 divisors (see below), whose sum is σ = 47146363103700. Its totient is φ = 8111202252160.

The previous prime is 21002220120019. The next prime is 21002220120191. The reversal of 21002220120100 is 102102220012.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 378124146724 + 20624095973376 = 614918^2 + 4541376^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3621069535 + ... + 3621075334.

It is an arithmetic number, because the mean of its divisors is an integer number (1309621197325).

Almost surely, 2^{21002220120100} is an apocalyptic number.

21002220120100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002220120100 is an abundant number, since it is smaller than the sum of its proper divisors (26144142983600).

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

21002220120100 is a wasteful number, since it uses less digits than its factorization.

21002220120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7242144912 (or 7242144905 counting only the distinct ones).

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

Adding to 21002220120100 its reverse (102102220012), we get a palindrome (21104322340112).

The spelling of 21002220120100 in words is "twenty-one trillion, two billion, two hundred twenty million, one hundred twenty thousand, one hundred".