210021200100 has 108 divisors (see below), whose sum is σ = 658896512820. Its totient is φ = 55954886400.

The previous prime is 210021200071. The next prime is 210021200119. The reversal of 210021200100 is 1002120012.

It can be written as a sum of positive squares in 6 ways, for example, as 15312577536 + 194708622564 = 123744^2 + 441258^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 892890 + ... + 1103310.

Almost surely, 2^210021200100 is an apocalyptic number.

210021200100 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 210021200100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329448256410).

210021200100 is an abundant number, since it is smaller than the sum of its proper divisors (448875312720).

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

210021200100 is a wasteful number, since it uses less digits than its factorization.

210021200100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211550 (or 211540 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 210021200100 its reverse (1002120012), we get a palindrome (211023320112).

The spelling of 210021200100 in words is "two hundred ten billion, twenty-one million, two hundred thousand, one hundred".