21324120 has 64 divisors (see below), whose sum is σ = 67741920. Its totient is φ = 5351424.

The previous prime is 21324119. The next prime is 21324139. The reversal of 21324120 is 2142312.

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

It is a zygodrome in base 9.

It is a self number, because there is not a number n which added to its sum of digits gives 21324120.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3187 + ... + 7266.

Almost surely, 2^21324120 is an apocalyptic number.

21324120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21324120 is an abundant number, since it is smaller than the sum of its proper divisors (46417800).

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

21324120 is a wasteful number, since it uses less digits than its factorization.

21324120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10484 (or 10480 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 21324120 is about 4617.8046732186. The cubic root of 21324120 is about 277.3045779378.

Adding to 21324120 its reverse (2142312), we get a palindrome (23466432).

The spelling of 21324120 in words is "twenty-one million, three hundred twenty-four thousand, one hundred twenty".