21012200 has 48 divisors (see below), whose sum is σ = 53300160. Its totient is φ = 7640000.

The previous prime is 21012193. The next prime is 21012227. The reversal of 21012200 is 221012.

It is a Harshad number since it is a multiple of its sum of digits (8).

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 11 ways as a sum of consecutive naturals, for example, 2576 + ... + 6975.

It is an arithmetic number, because the mean of its divisors is an integer number (1110420).

Almost surely, 2^21012200 is an apocalyptic number.

21012200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012200 is an abundant number, since it is smaller than the sum of its proper divisors (32287960).

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

21012200 is a wasteful number, since it uses less digits than its factorization.

21012200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9578 (or 9569 counting only the distinct ones).

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

The square root of 21012200 is about 4583.9066308118. The cubic root of 21012200 is about 275.9458340809.

Adding to 21012200 its reverse (221012), we get a palindrome (21233212).

It can be divided in two parts, 21012 and 200, that added together give a palindrome (21212).

The spelling of 21012200 in words is "twenty-one million, twelve thousand, two hundred".