643234787 has 6 divisors (see below), whose sum is σ = 696520692. Its totient is φ = 593755032.

The previous prime is 643234777. The next prime is 643234799. The reversal of 643234787 is 787432346.

It is not a de Polignac number, because 643234787 - 2¹⁶ = 643169251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643234727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1902893 + ... + 1903230.

It is an arithmetic number, because the mean of its divisors is an integer number (116086782).

Almost surely, 2^643234787 is an apocalyptic number.

643234787 is a deficient number, since it is larger than the sum of its proper divisors (53285905).

643234787 is a wasteful number, since it uses less digits than its factorization.

643234787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3806149 (or 3806136 counting only the distinct ones).

The product of its digits is 677376, while the sum is 44.

The square root of 643234787 is about 25362.0737913917. The cubic root of 643234787 is about 863.2233403231.

The spelling of 643234787 in words is "six hundred forty-three million, two hundred thirty-four thousand, seven hundred eighty-seven".