21300520447 has 12 divisors (see below), whose sum is σ = 22632506640. Its totient is φ = 20042844416.

The previous prime is 21300520441. The next prime is 21300520487. The reversal of 21300520447 is 74402500312.

It is a de Polignac number, because none of the positive numbers 2^k-21300520447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300520441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2193579 + ... + 2203267.

It is an arithmetic number, because the mean of its divisors is an integer number (1886042220).

Almost surely, 2^21300520447 is an apocalyptic number.

21300520447 is a deficient number, since it is larger than the sum of its proper divisors (1331986193).

21300520447 is an equidigital number, since it uses as much as digits as its factorization.

21300520447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17330 (or 17313 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 28.

The spelling of 21300520447 in words is "twenty-one billion, three hundred million, five hundred twenty thousand, four hundred forty-seven".