643041017 has 4 divisors (see below), whose sum is σ = 643457700. Its totient is φ = 642624336.

The previous prime is 643041011. The next prime is 643041079. The reversal of 643041017 is 710140346.

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

It can be written as a sum of positive squares in 2 ways, for example, as 147355321 + 495685696 = 12139^2 + 22264^2 .

It is not a de Polignac number, because 643041017 - 2⁶ = 643040953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643041011) 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, 206018 + ... + 209115.

It is an arithmetic number, because the mean of its divisors is an integer number (160864425).

Almost surely, 2^643041017 is an apocalyptic number.

It is an amenable number.

643041017 is a deficient number, since it is larger than the sum of its proper divisors (416683).

643041017 is a wasteful number, since it uses less digits than its factorization.

643041017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416682.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 643041017 is about 25358.2534296035. The cubic root of 643041017 is about 863.1366516111.

The spelling of 643041017 in words is "six hundred forty-three million, forty-one thousand, seventeen".