643065123 has 4 divisors (see below), whose sum is σ = 857420168. Its totient is φ = 428710080.

The previous prime is 643065121. The next prime is 643065133. The reversal of 643065123 is 321560346.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 643065123 - 2¹ = 643065121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643065121) 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 in 3 ways as a sum of consecutive naturals, for example, 107177518 + ... + 107177523.

It is an arithmetic number, because the mean of its divisors is an integer number (214355042).

Almost surely, 2^643065123 is an apocalyptic number.

643065123 is a deficient number, since it is larger than the sum of its proper divisors (214355045).

643065123 is a wasteful number, since it uses less digits than its factorization.

643065123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214355044.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 643065123 is about 25358.7287339094. The cubic root of 643065123 is about 863.1474370881.

The spelling of 643065123 in words is "six hundred forty-three million, sixty-five thousand, one hundred twenty-three".