1643543 has 18 divisors (see below), whose sum is σ = 1959888. Its totient is φ = 1376320.

The previous prime is 1643539. The next prime is 1643581. The reversal of 1643543 is 3453461.

It is not a de Polignac number, because 1643543 - 2² = 1643539 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 (1643513) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 34946 + ... + 34992.

2^1643543 is an apocalyptic number.

1643543 is a deficient number, since it is larger than the sum of its proper divisors (316345).

1643543 is a wasteful number, since it uses less digits than its factorization.

1643543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 75 counting only the distinct ones).

The product of its digits is 4320, while the sum is 26.

The square root of 1643543 is about 1282.0074102750. The cubic root of 1643543 is about 118.0122318068.

The spelling of 1643543 in words is "one million, six hundred forty-three thousand, five hundred forty-three".