639734 has 8 divisors (see below), whose sum is σ = 969408. Its totient is φ = 316600.

The previous prime is 639731. The next prime is 639739. The reversal of 639734 is 437936.

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

It is a self number, because there is not a number n which added to its sum of digits gives 639734.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639731) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1382 + ... + 1785.

It is an arithmetic number, because the mean of its divisors is an integer number (121176).

2⁶³⁹⁷³⁴ is an apocalyptic number.

639734 is a deficient number, since it is larger than the sum of its proper divisors (329674).

639734 is a wasteful number, since it uses less digits than its factorization.

639734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3270.

The product of its digits is 13608, while the sum is 32.

The square root of 639734 is about 799.8337327220. The cubic root of 639734 is about 86.1654467879.

The spelling of 639734 in words is "six hundred thirty-nine thousand, seven hundred thirty-four".