643393 has 4 divisors (see below), whose sum is σ = 660820. Its totient is φ = 625968.

The previous prime is 643373. The next prime is 643403. The reversal of 643393 is 393346.

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 501264 + 142129 = 708^2 + 377^2 .

It is a cyclic number.

It is not a de Polignac number, because 643393 - 2⁹ = 642881 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643303) 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, 8658 + ... + 8731.

It is an arithmetic number, because the mean of its divisors is an integer number (165205).

2⁶⁴³³⁹³ is an apocalyptic number.

It is an amenable number.

643393 is a deficient number, since it is larger than the sum of its proper divisors (17427).

643393 is a wasteful number, since it uses less digits than its factorization.

643393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17426.

The product of its digits is 5832, while the sum is 28.

The square root of 643393 is about 802.1178217693. The cubic root of 643393 is about 86.3294108655.

Subtracting from 643393 its reverse (393346), we obtain a cube (250047 = 63³).

The spelling of 643393 in words is "six hundred forty-three thousand, three hundred ninety-three".