16543643 has 4 divisors (see below), whose sum is σ = 16743048. Its totient is φ = 16344240.

The previous prime is 16543633. The next prime is 16543651. The reversal of 16543643 is 34634561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34634561 = 13 ⋅2664197.

It is a cyclic number.

It is not a de Polignac number, because 16543643 - 2¹² = 16539547 is a prime.

It is a super-2 number, since 2×16543643² = 547384247422898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16543603) 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, 99578 + ... + 99743.

It is an arithmetic number, because the mean of its divisors is an integer number (4185762).

Almost surely, 2^16543643 is an apocalyptic number.

16543643 is a deficient number, since it is larger than the sum of its proper divisors (199405).

16543643 is an equidigital number, since it uses as much as digits as its factorization.

16543643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199404.

The product of its digits is 25920, while the sum is 32.

The square root of 16543643 is about 4067.3877366192. The cubic root of 16543643 is about 254.8064300562.

The spelling of 16543643 in words is "sixteen million, five hundred forty-three thousand, six hundred forty-three".