21210100000 has 144 divisors (see below), whose sum is σ = 52683331176. Its totient is φ = 8404480000.

The previous prime is 21210099979. The next prime is 21210100027. The reversal of 21210100000 is 101212.

It can be written as a sum of positive squares in 12 ways, for example, as 15208808976 + 6001291024 = 123324^2 + 77468^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11299062 + ... + 11300938.

Almost surely, 2^21210100000 is an apocalyptic number.

21210100000 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 21210100000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26341665588).

21210100000 is an abundant number, since it is smaller than the sum of its proper divisors (31473231176).

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

21210100000 is an equidigital number, since it uses as much as digits as its factorization.

21210100000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2025 (or 1997 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21210100000 its reverse (101212), we get a palindrome (21210201212).

The spelling of 21210100000 in words is "twenty-one billion, two hundred ten million, one hundred thousand".