21304992 has 48 divisors (see below), whose sum is σ = 58363200. Its totient is φ = 6792192.

The previous prime is 21304991. The next prime is 21305003. The reversal of 21304992 is 29940312.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2617 + ... + 7032.

It is an arithmetic number, because the mean of its divisors is an integer number (1215900).

Almost surely, 2^21304992 is an apocalyptic number.

It is an amenable number.

21304992 is an abundant number, since it is smaller than the sum of its proper divisors (37058208).

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

21304992 is a wasteful number, since it uses less digits than its factorization.

21304992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9685 (or 9677 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 21304992 is about 4615.7330945366. The cubic root of 21304992 is about 277.2216379187.

The spelling of 21304992 in words is "twenty-one million, three hundred four thousand, nine hundred ninety-two".