21120300 has 108 divisors (see below), whose sum is σ = 68426176. Its totient is φ = 5443200.

The previous prime is 21120283. The next prime is 21120311. The reversal of 21120300 is 302112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

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, 27522 + ... + 28278.

Almost surely, 2^21120300 is an apocalyptic number.

21120300 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 21120300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34213088).

21120300 is an abundant number, since it is smaller than the sum of its proper divisors (47305876).

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

21120300 is a wasteful number, since it uses less digits than its factorization.

21120300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 808 (or 798 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 21120300 is about 4595.6827566750. The cubic root of 21120300 is about 276.4182379865.

Adding to 21120300 its reverse (302112), we get a palindrome (21422412).

The spelling of 21120300 in words is "twenty-one million, one hundred twenty thousand, three hundred".