21384856907 has 4 divisors (see below), whose sum is σ = 21392521776. Its totient is φ = 21377192040.

The previous prime is 21384856891. The next prime is 21384856921. The reversal of 21384856907 is 70965848312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21384856907 - 2⁴ = 21384856891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21384856007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3828248 + ... + 3833829.

It is an arithmetic number, because the mean of its divisors is an integer number (5348130444).

It is a 1-persistent number, because it is pandigital, but 2⋅21384856907 = 42769713814 is not.

Almost surely, 2^21384856907 is an apocalyptic number.

21384856907 is a deficient number, since it is larger than the sum of its proper divisors (7664869).

21384856907 is an equidigital number, since it uses as much as digits as its factorization.

21384856907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7664868.

The product of its (nonzero) digits is 2903040, while the sum is 53.

The spelling of 21384856907 in words is "twenty-one billion, three hundred eighty-four million, eight hundred fifty-six thousand, nine hundred seven".