646873 has 2 divisors, whose sum is σ = 646874. Its totient is φ = 646872.

The previous prime is 646859. The next prime is 646879. The reversal of 646873 is 378646.

646873 is nontrivially palindromic in base 16.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 635209 + 11664 = 797^2 + 108^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646873 is a prime.

It is not a weakly prime, because it can be changed into another prime (646879) 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, 323436 + 323437.

It is an arithmetic number, because the mean of its divisors is an integer number (323437).

2⁶⁴⁶⁸⁷³ is an apocalyptic number.

It is an amenable number.

646873 is a deficient number, since it is larger than the sum of its proper divisors (1).

646873 is an equidigital number, since it uses as much as digits as its factorization.

646873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 34.

The square root of 646873 is about 804.2841537666. The cubic root of 646873 is about 86.4847779690.

The spelling of 646873 in words is "six hundred forty-six thousand, eight hundred seventy-three".