21135300 has 36 divisors (see below), whose sum is σ = 61152336. Its totient is φ = 5636000.

The previous prime is 21135293. The next prime is 21135311. The reversal of 21135300 is 353112.

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 21135300.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 34926 + ... + 35525.

It is an arithmetic number, because the mean of its divisors is an integer number (1698676).

Almost surely, 2^21135300 is an apocalyptic number.

21135300 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21135300 is an abundant number, since it is smaller than the sum of its proper divisors (40017036).

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

21135300 is a wasteful number, since it uses less digits than its factorization.

21135300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70468 (or 70461 counting only the distinct ones).

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

The square root of 21135300 is about 4597.3144334492. The cubic root of 21135300 is about 276.4836614949.

Adding to 21135300 its reverse (353112), we get a palindrome (21488412).

It can be divided in two parts, 211 and 35300, that added together give a triangular number (35511 = T₂₆₆).

The spelling of 21135300 in words is "twenty-one million, one hundred thirty-five thousand, three hundred".