21204112000 has 128 divisors (see below), whose sum is σ = 52929676800. Its totient is φ = 8447718400.

The previous prime is 21204111991. The next prime is 21204112001. The reversal of 21204112000 is 21140212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×21204112000² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21204112001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4205481 + ... + 4210519.

It is an arithmetic number, because the mean of its divisors is an integer number (413513100).

Almost surely, 2^21204112000 is an apocalyptic number.

21204112000 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 21204112000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26464838400).

21204112000 is an abundant number, since it is smaller than the sum of its proper divisors (31725564800).

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

21204112000 is an equidigital number, since it uses as much as digits as its factorization.

21204112000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5331 (or 5309 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21204112000 its reverse (21140212), we get a palindrome (21225252212).

The spelling of 21204112000 in words is "twenty-one billion, two hundred four million, one hundred twelve thousand".