639393 has 4 divisors (see below), whose sum is σ = 852528. Its totient is φ = 426260.

The previous prime is 639391. The next prime is 639433. The reversal of 639393 is 393936.

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 not a de Polignac number, because 639393 - 2¹ = 639391 is a prime.

It is a D-number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (639391) 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, 106563 + ... + 106568.

It is an arithmetic number, because the mean of its divisors is an integer number (213132).

2⁶³⁹³⁹³ is an apocalyptic number.

It is an amenable number.

639393 is a deficient number, since it is larger than the sum of its proper divisors (213135).

639393 is a wasteful number, since it uses less digits than its factorization.

639393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213134.

The product of its digits is 13122, while the sum is 33.

The square root of 639393 is about 799.6205350039. The cubic root of 639393 is about 86.1501343614.

The spelling of 639393 in words is "six hundred thirty-nine thousand, three hundred ninety-three".