21047483809 has 16 divisors (see below), whose sum is σ = 23194604160. Its totient is φ = 18939490560.

The previous prime is 21047483803. The next prime is 21047483851. The reversal of 21047483809 is 90838474012.

It is a cyclic number.

It is not a de Polignac number, because 21047483809 - 2³ = 21047483801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21047483801) 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 15 ways as a sum of consecutive naturals, for example, 4517209 + ... + 4521865.

It is an arithmetic number, because the mean of its divisors is an integer number (1449662760).

Almost surely, 2^21047483809 is an apocalyptic number.

It is an amenable number.

21047483809 is a deficient number, since it is larger than the sum of its proper divisors (2147120351).

21047483809 is a wasteful number, since it uses less digits than its factorization.

21047483809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8760.

The product of its (nonzero) digits is 387072, while the sum is 46.

The spelling of 21047483809 in words is "twenty-one billion, forty-seven million, four hundred eighty-three thousand, eight hundred nine".