646543 has 2 divisors, whose sum is σ = 646544. Its totient is φ = 646542.

The previous prime is 646537. The next prime is 646549. The reversal of 646543 is 345646.

It is a balanced prime because it is at equal distance from previous prime (646537) and next prime (646549).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (646549) 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, 323271 + 323272.

It is an arithmetic number, because the mean of its divisors is an integer number (323272).

2⁶⁴⁶⁵⁴³ is an apocalyptic number.

646543 is a deficient number, since it is larger than the sum of its proper divisors (1).

646543 is an equidigital number, since it uses as much as digits as its factorization.

646543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8640, while the sum is 28.

The square root of 646543 is about 804.0789762206. The cubic root of 646543 is about 86.4700688317.

The spelling of 646543 in words is "six hundred forty-six thousand, five hundred forty-three".