646393 has 4 divisors (see below), whose sum is σ = 705168. Its totient is φ = 587620.

The previous prime is 646379. The next prime is 646397. The reversal of 646393 is 393646.

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 not a de Polignac number, because 646393 - 2¹³ = 638201 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (646397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29371 + ... + 29392.

It is an arithmetic number, because the mean of its divisors is an integer number (176292).

2⁶⁴⁶³⁹³ is an apocalyptic number.

It is an amenable number.

646393 is a deficient number, since it is larger than the sum of its proper divisors (58775).

646393 is a wasteful number, since it uses less digits than its factorization.

646393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58774.

The product of its digits is 11664, while the sum is 31.

The square root of 646393 is about 803.9856963902. The cubic root of 646393 is about 86.4633812056.

It can be divided in two parts, 6463 and 93, that added together give a palindrome (6556).

The spelling of 646393 in words is "six hundred forty-six thousand, three hundred ninety-three".