210021100100100 has 432 divisors, whose sum is σ = 685907373649680. Its totient is φ = 53704949760000.

The previous prime is 210021100100099. The next prime is 210021100100107. The reversal of 210021100100100 is 1001001120012.

It is a happy number.

It can be written as a sum of positive squares in 24 ways, for example, as 206841233664576 + 3179866435524 = 14381976^2 + 1783218^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (210021100100107) by changing a digit.

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 143 ways as a sum of consecutive naturals, for example, 3171484990 + ... + 3171551210.

It is an arithmetic number, because the mean of its divisors is an integer number (1587748550115).

Almost surely, 2^{210021100100100} is an apocalyptic number.

210021100100100 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 210021100100100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342953686824840).

210021100100100 is an abundant number, since it is smaller than the sum of its proper divisors (475886273549580).

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

210021100100100 is a wasteful number, since it uses less digits than its factorization.

210021100100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67752 (or 67742 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 210021100100100 its reverse (1001001120012), we get a palindrome (211022101220112).

The spelling of 210021100100100 in words is "two hundred ten trillion, twenty-one billion, one hundred million, one hundred thousand, one hundred".