21109300 has 18 divisors (see below), whose sum is σ = 45807398. Its totient is φ = 8443680.

The previous prime is 21109273. The next prime is 21109313. The reversal of 21109300 is 390112.

It can be written as a sum of positive squares in 3 ways, for example, as 206116 + 20903184 = 454^2 + 4572^2 .

It is a congruent number.

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, 105447 + ... + 105646.

Almost surely, 2^21109300 is an apocalyptic number.

21109300 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21109300 is an abundant number, since it is smaller than the sum of its proper divisors (24698098).

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

21109300 is a wasteful number, since it uses less digits than its factorization.

21109300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211107 (or 211100 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 21109300 is about 4594.4858254216. The cubic root of 21109300 is about 276.3702410571.

Adding to 21109300 its reverse (390112), we get a palindrome (21499412).

The spelling of 21109300 in words is "twenty-one million, one hundred nine thousand, three hundred".