646169 has 2 divisors, whose sum is σ = 646170. Its totient is φ = 646168.

The previous prime is 646159. The next prime is 646181. The reversal of 646169 is 961646.

646169 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 375769 + 270400 = 613^2 + 520^2 .

It is a cyclic number.

It is not a de Polignac number, because 646169 - 2¹⁶ = 580633 is a prime.

It is a super-2 number, since 2×646169² = 835068753122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (646159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323084 + 323085.

It is an arithmetic number, because the mean of its divisors is an integer number (323085).

2⁶⁴⁶¹⁶⁹ is an apocalyptic number.

It is an amenable number.

646169 is a deficient number, since it is larger than the sum of its proper divisors (1).

646169 is an equidigital number, since it uses as much as digits as its factorization.

646169 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 32.

The square root of 646169 is about 803.8463783585. The cubic root of 646169 is about 86.4533924242.

The spelling of 646169 in words is "six hundred forty-six thousand, one hundred sixty-nine".