1643043 has 4 divisors (see below), whose sum is σ = 2190728. Its totient is φ = 1095360.

The previous prime is 1643039. The next prime is 1643069. The reversal of 1643043 is 3403461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3403461 = 3 ⋅1134487.

It is not a de Polignac number, because 1643043 - 2² = 1643039 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273838 + ... + 273843.

It is an arithmetic number, because the mean of its divisors is an integer number (547682).

2^1643043 is an apocalyptic number.

1643043 is a deficient number, since it is larger than the sum of its proper divisors (547685).

1643043 is an equidigital number, since it uses as much as digits as its factorization.

1643043 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547684.

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 1643043 is about 1281.8123887683. The cubic root of 1643043 is about 118.0002633337. Note that the first 3 decimals are identical.

The spelling of 1643043 in words is "one million, six hundred forty-three thousand, forty-three".