21221222020100 has 36 divisors (see below), whose sum is σ = 46052271411300. Its totient is φ = 8488079660160.

The previous prime is 21221222020087. The next prime is 21221222020111. The reversal of 21221222020100 is 102022212212.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 71503936 + 21221150516164 = 8456^2 + 4606642^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3025055 + ... + 7182854.

It is an arithmetic number, because the mean of its divisors is an integer number (1279229761425).

Almost surely, 2^{21221222020100} is an apocalyptic number.

21221222020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221222020100 is an abundant number, since it is smaller than the sum of its proper divisors (24831049391200).

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

21221222020100 is a wasteful number, since it uses less digits than its factorization.

21221222020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10228712 (or 10228705 counting only the distinct ones).

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

Adding to 21221222020100 its reverse (102022212212), we get a palindrome (21323244232312).

The spelling of 21221222020100 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, twenty thousand, one hundred".