21304472 has 32 divisors (see below), whose sum is σ = 48057600. Its totient is φ = 8649504.

The previous prime is 21304469. The next prime is 21304477. The reversal of 21304472 is 27440312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21304477) 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, 8948 + ... + 11075.

It is an arithmetic number, because the mean of its divisors is an integer number (1501800).

Almost surely, 2^21304472 is an apocalyptic number.

It is an amenable number.

21304472 is an abundant number, since it is smaller than the sum of its proper divisors (26753128).

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

21304472 is a wasteful number, since it uses less digits than its factorization.

21304472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20055 (or 20051 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 23.

The square root of 21304472 is about 4615.6767651126. The cubic root of 21304472 is about 277.2193824782.

Adding to 21304472 its reverse (27440312), we get a palindrome (48744784).

The spelling of 21304472 in words is "twenty-one million, three hundred four thousand, four hundred seventy-two".