21153300 has 108 divisors (see below), whose sum is σ = 71245440. Its totient is φ = 4831680.

The previous prime is 21153299. The next prime is 21153323. The reversal of 21153300 is 335112.

It is a happy number.

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 21153300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 13981 + ... + 15419.

It is an arithmetic number, because the mean of its divisors is an integer number (659680).

Almost surely, 2^21153300 is an apocalyptic number.

21153300 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 21153300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35622720).

21153300 is an abundant number, since it is smaller than the sum of its proper divisors (50092140).

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

21153300 is a wasteful number, since it uses less digits than its factorization.

21153300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1470 (or 1456 counting only the distinct ones).

The product of its (nonzero) digits is 90, while the sum is 15.

The square root of 21153300 is about 4599.2716814731. The cubic root of 21153300 is about 276.5621288577.

Adding to 21153300 its reverse (335112), we get a palindrome (21488412).

The spelling of 21153300 in words is "twenty-one million, one hundred fifty-three thousand, three hundred".