21306300 has 144 divisors (see below), whose sum is σ = 66662400. Its totient is φ = 5241600.

The previous prime is 21306293. The next prime is 21306301. The reversal of 21306300 is 360312.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21306300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21306301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 269661 + ... + 269739.

Almost surely, 2^21306300 is an apocalyptic number.

21306300 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 21306300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33331200).

21306300 is an abundant number, since it is smaller than the sum of its proper divisors (45356100).

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

21306300 is a wasteful number, since it uses less digits than its factorization.

21306300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 21306300 is about 4615.8747816638. The cubic root of 21306300 is about 277.2273110568.

Adding to 21306300 its reverse (360312), we get a palindrome (21666612).

The spelling of 21306300 in words is "twenty-one million, three hundred six thousand, three hundred".