810643 has 2 divisors, whose sum is σ = 810644. Its totient is φ = 810642.

The previous prime is 810587. The next prime is 810653. The reversal of 810643 is 346018.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-810643 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (810653) 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, 405321 + 405322.

It is an arithmetic number, because the mean of its divisors is an integer number (405322).

2⁸¹⁰⁶⁴³ is an apocalyptic number.

810643 is a deficient number, since it is larger than the sum of its proper divisors (1).

810643 is an equidigital number, since it uses as much as digits as its factorization.

810643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 810643 is about 900.3571513572. The cubic root of 810643 is about 93.2416347102.

The spelling of 810643 in words is "eight hundred ten thousand, six hundred forty-three".