643910375 has 16 divisors (see below), whose sum is σ = 804323520. Its totient is φ = 514664800.

The previous prime is 643910359. The next prime is 643910383. The reversal of 643910375 is 573019346.

It is a happy number.

643910375 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643910375 - 2⁴ = 643910359 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 229481 + ... + 232269.

It is an arithmetic number, because the mean of its divisors is an integer number (50270220).

Almost surely, 2^643910375 is an apocalyptic number.

643910375 is a deficient number, since it is larger than the sum of its proper divisors (160413145).

643910375 is a wasteful number, since it uses less digits than its factorization.

643910375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4651 (or 4641 counting only the distinct ones).

The product of its (nonzero) digits is 68040, while the sum is 38.

The square root of 643910375 is about 25375.3891595774. The cubic root of 643910375 is about 863.5254484018.

The spelling of 643910375 in words is "six hundred forty-three million, nine hundred ten thousand, three hundred seventy-five".