639470 has 16 divisors (see below), whose sum is σ = 1239840. Its totient is φ = 236064.

The previous prime is 639451. The next prime is 639487. The reversal of 639470 is 74936.

It is a congruent number.

It is an unprimeable number.

639470 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2330 + ... + 2589.

It is an arithmetic number, because the mean of its divisors is an integer number (77490).

2⁶³⁹⁴⁷⁰ is an apocalyptic number.

639470 is a deficient number, since it is larger than the sum of its proper divisors (600370).

639470 is a wasteful number, since it uses less digits than its factorization.

639470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4939.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 639470 is about 799.6686813925. The cubic root of 639470 is about 86.1535924819.

The spelling of 639470 in words is "six hundred thirty-nine thousand, four hundred seventy".