639349 has 4 divisors (see below), whose sum is σ = 647136. Its totient is φ = 631564.

The previous prime is 639337. The next prime is 639361. The reversal of 639349 is 943936.

639349 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an interprime number because it is at equal distance from previous prime (639337) and next prime (639361).

It is a cyclic number.

It is not a de Polignac number, because 639349 - 2¹³ = 631157 is a prime.

It is a Duffinian number.

639349 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639329) 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, 3769 + ... + 3934.

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

2⁶³⁹³⁴⁹ is an apocalyptic number.

It is an amenable number.

639349 is a deficient number, since it is larger than the sum of its proper divisors (7787).

639349 is an equidigital number, since it uses as much as digits as its factorization.

639349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7786.

The product of its digits is 17496, while the sum is 34.

The square root of 639349 is about 799.5930214803. The cubic root of 639349 is about 86.1481581679.

The spelling of 639349 in words is "six hundred thirty-nine thousand, three hundred forty-nine".