21211300000 has 216 divisors, whose sum is σ = 57405567996. Its totient is φ = 7708800000.

The previous prime is 21211299961. The next prime is 21211300003. The reversal of 21211300000 is 311212.

It can be written as a sum of positive squares in 6 ways, for example, as 8033178384 + 13178121616 = 89628^2 + 114796^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a self number, because there is not a number n which added to its sum of digits gives 21211300000.

It is not an unprimeable number, because it can be changed into a prime (21211300003) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 12099124 + ... + 12100876.

Almost surely, 2^21211300000 is an apocalyptic number.

21211300000 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 21211300000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28702783998).

21211300000 is an abundant number, since it is smaller than the sum of its proper divisors (36194267996).

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

21211300000 is an equidigital number, since it uses as much as digits as its factorization.

21211300000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1810 (or 1771 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 10.

Adding to 21211300000 its reverse (311212), we get a palindrome (21211611212).

The spelling of 21211300000 in words is "twenty-one billion, two hundred eleven million, three hundred thousand".