1671643 has 2 divisors, whose sum is σ = 1671644. Its totient is φ = 1671642.

The previous prime is 1671641. The next prime is 1671671. The reversal of 1671643 is 3461761.

It is an a-pointer prime, because the next prime (1671671) can be obtained adding 1671643 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1671643 - 2¹ = 1671641 is a prime.

Together with 1671641, it forms a pair of twin primes.

1671643 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (1671641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 835821 + 835822.

It is an arithmetic number, because the mean of its divisors is an integer number (835822).

2^1671643 is an apocalyptic number.

1671643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1671643 is an equidigital number, since it uses as much as digits as its factorization.

1671643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 1671643 is about 1292.9203378399. The cubic root of 1671643 is about 118.6809948122.

The spelling of 1671643 in words is "one million, six hundred seventy-one thousand, six hundred forty-three".