643870703 has 4 divisors (see below), whose sum is σ = 735852240. Its totient is φ = 551889168.

The previous prime is 643870679. The next prime is 643870751. The reversal of 643870703 is 307078346.

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

It is a cyclic number.

It is not a de Polignac number, because 643870703 - 2¹⁴ = 643854319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643875703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45990758 + ... + 45990771.

It is an arithmetic number, because the mean of its divisors is an integer number (183963060).

Almost surely, 2^643870703 is an apocalyptic number.

643870703 is a deficient number, since it is larger than the sum of its proper divisors (91981537).

643870703 is an equidigital number, since it uses as much as digits as its factorization.

643870703 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91981536.

The product of its (nonzero) digits is 84672, while the sum is 38.

The square root of 643870703 is about 25374.6074452394. The cubic root of 643870703 is about 863.5077137985.

The spelling of 643870703 in words is "six hundred forty-three million, eight hundred seventy thousand, seven hundred three".