639587 has 4 divisors (see below), whose sum is σ = 688800. Its totient is φ = 590376.

The previous prime is 639577. The next prime is 639589. The reversal of 639587 is 785936.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 639587 - 2⁴ = 639571 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639587.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639587.

It is not an unprimeable number, because it can be changed into a prime (639589) 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, 24587 + ... + 24612.

It is an arithmetic number, because the mean of its divisors is an integer number (172200).

2⁶³⁹⁵⁸⁷ is an apocalyptic number.

639587 is a deficient number, since it is larger than the sum of its proper divisors (49213).

639587 is a wasteful number, since it uses less digits than its factorization.

639587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49212.

The product of its digits is 45360, while the sum is 38.

The square root of 639587 is about 799.7418333437. The cubic root of 639587 is about 86.1588464973.

It can be divided in two parts, 6 and 39587, that added together give a palindrome (39593).

The spelling of 639587 in words is "six hundred thirty-nine thousand, five hundred eighty-seven".