16881812509 has 4 divisors (see below), whose sum is σ = 16902995004. Its totient is φ = 16860630016.

The previous prime is 16881812501. The next prime is 16881812537. The reversal of 16881812509 is 90521818861.

16881812509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5076990009 + 11804822500 = 71253^2 + 108650^2 .

It is a cyclic number.

It is not a de Polignac number, because 16881812509 - 2³ = 16881812501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16881812501) 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, 10590052 + ... + 10591645.

It is an arithmetic number, because the mean of its divisors is an integer number (4225748751).

Almost surely, 2^16881812509 is an apocalyptic number.

It is an amenable number.

16881812509 is a deficient number, since it is larger than the sum of its proper divisors (21182495).

16881812509 is an equidigital number, since it uses as much as digits as its factorization.

16881812509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21182494.

The product of its (nonzero) digits is 276480, while the sum is 49.

The spelling of 16881812509 in words is "sixteen billion, eight hundred eighty-one million, eight hundred twelve thousand, five hundred nine".