643610113 has 2 divisors, whose sum is σ = 643610114. Its totient is φ = 643610112.

The previous prime is 643610069. The next prime is 643610131. The reversal of 643610113 is 311016346.

It is a happy number.

Together with next prime (643610131) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 448253584 + 195356529 = 21172^2 + 13977^2 .

It is a cyclic number.

It is not a de Polignac number, because 643610113 - 2²⁵ = 610055681 is a prime.

It is not a weakly prime, because it can be changed into another prime (643610183) 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, 321805056 + 321805057.

It is an arithmetic number, because the mean of its divisors is an integer number (321805057).

Almost surely, 2^643610113 is an apocalyptic number.

It is an amenable number.

643610113 is a deficient number, since it is larger than the sum of its proper divisors (1).

643610113 is an equidigital number, since it uses as much as digits as its factorization.

643610113 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 643610113 is about 25369.4720678220. The cubic root of 643610113 is about 863.3912039474.

Adding to 643610113 its reverse (311016346), we get a palindrome (954626459).

The spelling of 643610113 in words is "six hundred forty-three million, six hundred ten thousand, one hundred thirteen".