21020221100 has 18 divisors (see below), whose sum is σ = 45613880004. Its totient is φ = 8408088400.

The previous prime is 21020221097. The next prime is 21020221121. The reversal of 21020221100 is 112202012.

It is a happy number.

It is a super-3 number, since 3×21020221100³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105101006 + ... + 105101205.

Almost surely, 2^21020221100 is an apocalyptic number.

21020221100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020221100 is an abundant number, since it is smaller than the sum of its proper divisors (24593658904).

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

21020221100 is a wasteful number, since it uses less digits than its factorization.

21020221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210202225 (or 210202218 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21020221100 its reverse (112202012), we get a palindrome (21132423112).

The spelling of 21020221100 in words is "twenty-one billion, twenty million, two hundred twenty-one thousand, one hundred".