21021001221100 has 18 divisors (see below), whose sum is σ = 45615572650004. Its totient is φ = 8408400488400.

The previous prime is 21021001221089. The next prime is 21021001221109. The reversal of 21021001221100 is 112210012012.

It is not an unprimeable number, because it can be changed into a prime (21021001221109) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105105006006 + ... + 105105006205.

Almost surely, 2^{21021001221100} is an apocalyptic number.

21021001221100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021001221100 is an abundant number, since it is smaller than the sum of its proper divisors (24594571428904).

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

21021001221100 is a wasteful number, since it uses less digits than its factorization.

21021001221100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210210012225 (or 210210012218 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21021001221100 its reverse (112210012012), we get a palindrome (21133211233112).

The spelling of 21021001221100 in words is "twenty-one trillion, twenty-one billion, one million, two hundred twenty-one thousand, one hundred".