1645543 has 2 divisors, whose sum is σ = 1645544. Its totient is φ = 1645542.

The previous prime is 1645537. The next prime is 1645559. The reversal of 1645543 is 3455461.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1645543 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1645643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822771 + 822772.

It is an arithmetic number, because the mean of its divisors is an integer number (822772).

2^1645543 is an apocalyptic number.

1645543 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645543 is an equidigital number, since it uses as much as digits as its factorization.

1645543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 28.

The square root of 1645543 is about 1282.7871998114. The cubic root of 1645543 is about 118.0600814402.

The spelling of 1645543 in words is "one million, six hundred forty-five thousand, five hundred forty-three".