21011300 has 18 divisors (see below), whose sum is σ = 45594738. Its totient is φ = 8404480.

The previous prime is 21011299. The next prime is 21011317. The reversal of 21011300 is 311012.

It can be written as a sum of positive squares in 3 ways, for example, as 3655744 + 17355556 = 1912^2 + 4166^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 104957 + ... + 105156.

It is an arithmetic number, because the mean of its divisors is an integer number (2533041).

Almost surely, 2^21011300 is an apocalyptic number.

21011300 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011300 is an abundant number, since it is smaller than the sum of its proper divisors (24583438).

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

21011300 is a wasteful number, since it uses less digits than its factorization.

21011300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210127 (or 210120 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 21011300 is about 4583.8084602217. The cubic root of 21011300 is about 275.9418942302.

Adding to 21011300 its reverse (311012), we get a palindrome (21322312).

The spelling of 21011300 in words is "twenty-one million, eleven thousand, three hundred".