21305296 has 40 divisors (see below), whose sum is σ = 42720480. Its totient is φ = 10286976.

The previous prime is 21305293. The next prime is 21305309. The reversal of 21305296 is 69250312.

It is a super-3 number, since 3×21305296³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21305293) 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 7 ways as a sum of consecutive naturals, for example, 118935 + ... + 119113.

It is an arithmetic number, because the mean of its divisors is an integer number (1068012).

Almost surely, 2^21305296 is an apocalyptic number.

It is an amenable number.

21305296 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

21305296 is a wasteful number, since it uses less digits than its factorization.

21305296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21305296 is about 4615.7660252660. The cubic root of 21305296 is about 277.2229564669. Note that the first 3 decimals are identical.

The spelling of 21305296 in words is "twenty-one million, three hundred five thousand, two hundred ninety-six".