21011200 has 162 divisors, whose sum is σ = 61399716. Its totient is φ = 7096320.

The previous prime is 21011191. The next prime is 21011231. The reversal of 21011200 is 211012.

It is a Harshad number since it is a multiple of its sum of digits (7).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 313567 + ... + 313633.

Almost surely, 2^21011200 is an apocalyptic number.

21011200 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 21011200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30699858).

21011200 is an abundant number, since it is smaller than the sum of its proper divisors (40388516).

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

21011200 is an equidigital number, since it uses as much as digits as its factorization.

21011200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 81 counting only the distinct ones).

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

The square root of 21011200 is about 4583.7975522486. The cubic root of 21011200 is about 275.9414564620.

Adding to 21011200 its reverse (211012), we get a palindrome (21222212).

The spelling of 21011200 in words is "twenty-one million, eleven thousand, two hundred".