21330447 has 8 divisors (see below), whose sum is σ = 28922880. Its totient is φ = 13979160.

The previous prime is 21330443. The next prime is 21330467. The reversal of 21330447 is 74403312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21330447 - 2² = 21330443 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 60079 + ... + 60432.

It is an arithmetic number, because the mean of its divisors is an integer number (3615360).

Almost surely, 2^21330447 is an apocalyptic number.

21330447 is a deficient number, since it is larger than the sum of its proper divisors (7592433).

21330447 is a wasteful number, since it uses less digits than its factorization.

21330447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120573.

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 21330447 is about 4618.4896881989. The cubic root of 21330447 is about 277.3320012276.

Adding to 21330447 its reverse (74403312), we get a palindrome (95733759).

The spelling of 21330447 in words is "twenty-one million, three hundred thirty thousand, four hundred forty-seven".