643163723 has 2 divisors, whose sum is σ = 643163724. Its totient is φ = 643163722.

The previous prime is 643163713. The next prime is 643163767. The reversal of 643163723 is 327361346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643163723 - 2⁴ = 643163707 is a prime.

It is not a weakly prime, because it can be changed into another prime (643163713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321581861 + 321581862.

It is an arithmetic number, because the mean of its divisors is an integer number (321581862).

Almost surely, 2^643163723 is an apocalyptic number.

643163723 is a deficient number, since it is larger than the sum of its proper divisors (1).

643163723 is an equidigital number, since it uses as much as digits as its factorization.

643163723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 35.

The square root of 643163723 is about 25360.6727631583. The cubic root of 643163723 is about 863.1915497732.

The spelling of 643163723 in words is "six hundred forty-three million, one hundred sixty-three thousand, seven hundred twenty-three".