21220021020100 has 288 divisors, whose sum is σ = 54929099423744. Its totient is φ = 6962344243200.

The previous prime is 21220021020067. The next prime is 21220021020101. The reversal of 21220021020100 is 102012002212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21220021020101) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3045786817 + ... + 3045793783.

Almost surely, 2^{21220021020100} is an apocalyptic number.

21220021020100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21220021020100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27464549711872).

21220021020100 is an abundant number, since it is smaller than the sum of its proper divisors (33709078403644).

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

21220021020100 is a wasteful number, since it uses less digits than its factorization.

21220021020100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8563 (or 8556 counting only the distinct ones).

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

Adding to 21220021020100 its reverse (102012002212), we get a palindrome (21322033022312).

The spelling of 21220021020100 in words is "twenty-one trillion, two hundred twenty billion, twenty-one million, twenty thousand, one hundred".