639682 has 16 divisors (see below), whose sum is σ = 1020600. Its totient is φ = 300160.

The previous prime is 639679. The next prime is 639689. The reversal of 639682 is 286936.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 231361 + 408321 = 481^2 + 639^2 .

It is a super-2 number, since 2×639682² = 818386122248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (639689) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2244 + ... + 2512.

2⁶³⁹⁶⁸² is an apocalyptic number.

639682 is a deficient number, since it is larger than the sum of its proper divisors (380918).

639682 is a wasteful number, since it uses less digits than its factorization.

639682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341.

The product of its digits is 15552, while the sum is 34.

The square root of 639682 is about 799.8012253054. The cubic root of 639682 is about 86.1631121068.

The spelling of 639682 in words is "six hundred thirty-nine thousand, six hundred eighty-two".