210221100020 has 48 divisors (see below), whose sum is σ = 467510451408. Its totient is φ = 79128913920.

The previous prime is 210221099989. The next prime is 210221100029. The reversal of 210221100020 is 20001122012.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 275692816 + 209945407204 = 16604^2 + 458198^2 .

It is a junction number, because it is equal to n+sod(n) for n = 210221099974 and 210221100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210221100029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2134994 + ... + 2231286.

It is an arithmetic number, because the mean of its divisors is an integer number (9739801071).

Almost surely, 2^210221100020 is an apocalyptic number.

210221100020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

210221100020 is an abundant number, since it is smaller than the sum of its proper divisors (257289351388).

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

210221100020 is a wasteful number, since it uses less digits than its factorization.

210221100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102740 (or 102738 counting only the distinct ones).

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

Adding to 210221100020 its reverse (20001122012), we get a palindrome (230222222032).

The spelling of 210221100020 in words is "two hundred ten billion, two hundred twenty-one million, one hundred thousand, twenty".