646544089 has 2 divisors, whose sum is σ = 646544090. Its totient is φ = 646544088.

The previous prime is 646544083. The next prime is 646544111. The reversal of 646544089 is 980445646.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 330948864 + 315595225 = 18192^2 + 17765^2 .

It is a cyclic number.

It is not a de Polignac number, because 646544089 - 2⁹ = 646543577 is a prime.

It is a super-3 number, since 3×646544089³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (646544083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323272044 + 323272045.

It is an arithmetic number, because the mean of its divisors is an integer number (323272045).

Almost surely, 2^646544089 is an apocalyptic number.

It is an amenable number.

646544089 is a deficient number, since it is larger than the sum of its proper divisors (1).

646544089 is an equidigital number, since it uses as much as digits as its factorization.

646544089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 829440, while the sum is 46.

The square root of 646544089 is about 25427.2312491942. The cubic root of 646544089 is about 864.7011738005.

The spelling of 646544089 in words is "six hundred forty-six million, five hundred forty-four thousand, eighty-nine".