639567 has 12 divisors (see below), whose sum is σ = 931320. Its totient is φ = 422928.

The previous prime is 639563. The next prime is 639571. The reversal of 639567 is 765936.

It is a happy number.

639567 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (639563) and next prime (639571).

It is not a de Polignac number, because 639567 - 2² = 639563 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1413 + ... + 1809.

It is an arithmetic number, because the mean of its divisors is an integer number (77610).

2⁶³⁹⁵⁶⁷ is an apocalyptic number.

639567 is a deficient number, since it is larger than the sum of its proper divisors (291753).

639567 is a wasteful number, since it uses less digits than its factorization.

639567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582 (or 579 counting only the distinct ones).

The product of its digits is 34020, while the sum is 36.

The square root of 639567 is about 799.7293292108. The cubic root of 639567 is about 86.1579484204.

The spelling of 639567 in words is "six hundred thirty-nine thousand, five hundred sixty-seven".