643117 has 4 divisors (see below), whose sum is σ = 647136. Its totient is φ = 639100.

The previous prime is 643099. The next prime is 643121. The reversal of 643117 is 711346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643117 is a prime.

It is a Duffinian number.

643117 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643187) 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, 1759 + ... + 2092.

It is an arithmetic number, because the mean of its divisors is an integer number (161784).

2⁶⁴³¹¹⁷ is an apocalyptic number.

It is an amenable number.

643117 is a deficient number, since it is larger than the sum of its proper divisors (4019).

643117 is a wasteful number, since it uses less digits than its factorization.

643117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4018.

The product of its digits is 504, while the sum is 22.

The square root of 643117 is about 801.9457587643. The cubic root of 643117 is about 86.3170646918.

The spelling of 643117 in words is "six hundred forty-three thousand, one hundred seventeen".