16505398643 has 8 divisors (see below), whose sum is σ = 16544986080. Its totient is φ = 16465835520.

The previous prime is 16505398627. The next prime is 16505398661. The reversal of 16505398643 is 34689350561.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16505398643 - 2⁴ = 16505398627 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16505398591 and 16505398600.

It is not an unprimeable number, because it can be changed into a prime (16505398843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2646653 + ... + 2652881.

It is an arithmetic number, because the mean of its divisors is an integer number (2068123260).

Almost surely, 2^16505398643 is an apocalyptic number.

16505398643 is a deficient number, since it is larger than the sum of its proper divisors (39587437).

16505398643 is an equidigital number, since it uses as much as digits as its factorization.

16505398643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12157.

The product of its (nonzero) digits is 2332800, while the sum is 50.

The spelling of 16505398643 in words is "sixteen billion, five hundred five million, three hundred ninety-eight thousand, six hundred forty-three".