21200512 has 32 divisors (see below), whose sum is σ = 42732900. Its totient is φ = 10475520.

The previous prime is 21200507. The next prime is 21200521. The reversal of 21200512 is 21500212.

It can be written as a sum of positive squares in 2 ways, for example, as 15555136 + 5645376 = 3944^2 + 2376^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 21200492 and 21200501.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10462 + ... + 12322.

Almost surely, 2^21200512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21200512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21366450).

21200512 is an abundant number, since it is smaller than the sum of its proper divisors (21532388).

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

21200512 is an equidigital number, since it uses as much as digits as its factorization.

21200512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1964 (or 1952 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 21200512 is about 4604.4013725999. The cubic root of 21200512 is about 276.7677287603.

Adding to 21200512 its reverse (21500212), we get a palindrome (42700724).

It can be divided in two parts, 21200 and 512, that added together give a palindrome (21712).

The spelling of 21200512 in words is "twenty-one million, two hundred thousand, five hundred twelve".