639434 has 8 divisors (see below), whose sum is σ = 985188. Its totient is φ = 311040.

The previous prime is 639433. The next prime is 639439. The reversal of 639434 is 434936.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 635209 + 4225 = 797^2 + 65^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 639397 and 639406.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639434.

It is not an unprimeable number, because it can be changed into a prime (639433) 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, 4247 + ... + 4394.

2⁶³⁹⁴³⁴ is an apocalyptic number.

639434 is a deficient number, since it is larger than the sum of its proper divisors (345754).

639434 is a wasteful number, since it uses less digits than its factorization.

639434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8680.

The product of its digits is 7776, while the sum is 29.

The square root of 639434 is about 799.6461717535. The cubic root of 639434 is about 86.1519757329.

The spelling of 639434 in words is "six hundred thirty-nine thousand, four hundred thirty-four".