16509423409 has 4 divisors (see below), whose sum is σ = 16533596016. Its totient is φ = 16485250804.

The previous prime is 16509423407. The next prime is 16509423431. The reversal of 16509423409 is 90432490561.

16509423409 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, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90432490561 = 7 ⋅12918927223.

It is a cyclic number.

It is not a de Polignac number, because 16509423409 - 2¹ = 16509423407 is a prime.

It is a super-2 number, since 2×16509423409² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16509423407) 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, 12085279 + ... + 12086644.

It is an arithmetic number, because the mean of its divisors is an integer number (4133399004).

Almost surely, 2^16509423409 is an apocalyptic number.

It is an amenable number.

16509423409 is a deficient number, since it is larger than the sum of its proper divisors (24172607).

16509423409 is an equidigital number, since it uses as much as digits as its factorization.

16509423409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24172606.

The product of its (nonzero) digits is 233280, while the sum is 43.

The spelling of 16509423409 in words is "sixteen billion, five hundred nine million, four hundred twenty-three thousand, four hundred nine".