21304120 has 16 divisors (see below), whose sum is σ = 47934360. Its totient is φ = 8521632.

The previous prime is 21304117. The next prime is 21304121. The reversal of 21304120 is 2140312.

It is a self number, because there is not a number n which added to its sum of digits gives 21304120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266262 + ... + 266341.

Almost surely, 2^21304120 is an apocalyptic number.

21304120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21304120 is an abundant number, since it is smaller than the sum of its proper divisors (26630240).

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

21304120 is a wasteful number, since it uses less digits than its factorization.

21304120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532614 (or 532610 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21304120 is about 4615.6386340354. The cubic root of 21304120 is about 277.2178556977.

Adding to 21304120 its reverse (2140312), we get a palindrome (23444432).

The spelling of 21304120 in words is "twenty-one million, three hundred four thousand, one hundred twenty".