21330312 has 64 divisors (see below), whose sum is σ = 58104000. Its totient is φ = 6499584.

The previous prime is 21330311. The next prime is 21330313. The reversal of 21330312 is 21303312.

It is an interprime number because it is at equal distance from previous prime (21330311) and next prime (21330313).

It is a junction number, because it is equal to n+sod(n) for n = 21330291 and 21330300.

It is not an unprimeable number, because it can be changed into a prime (21330311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12418 + ... + 14030.

It is an arithmetic number, because the mean of its divisors is an integer number (907875).

Almost surely, 2^21330312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21330312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29052000).

21330312 is an abundant number, since it is smaller than the sum of its proper divisors (36773688).

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

21330312 is a wasteful number, since it uses less digits than its factorization.

21330312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1670 (or 1666 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 21330312 is about 4618.4750730084. The cubic root of 21330312 is about 277.3314161500.

Adding to 21330312 its reverse (21303312), we get a palindrome (42633624).

Subtracting from 21330312 its reverse (21303312), we obtain a cube (27000 = 30³).

The spelling of 21330312 in words is "twenty-one million, three hundred thirty thousand, three hundred twelve".