639576 has 96 divisors (see below), whose sum is σ = 2096640. Its totient is φ = 178848.

The previous prime is 639571. The next prime is 639577. The reversal of 639576 is 675936.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 639576.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639576.

It is not an unprimeable number, because it can be changed into a prime (639571) by changing a digit.

639576 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13585 + ... + 13631.

It is an arithmetic number, because the mean of its divisors is an integer number (21840).

2⁶³⁹⁵⁷⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1048320).

639576 is an abundant number, since it is smaller than the sum of its proper divisors (1457064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639576 is a wasteful number, since it uses less digits than its factorization.

639576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 59 counting only the distinct ones).

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

The square root of 639576 is about 799.7349560948. The cubic root of 639576 is about 86.1583525573.

639576 divided by its sum of digits (36) gives a triangular number (17766 = T₁₈₈).

The spelling of 639576 in words is "six hundred thirty-nine thousand, five hundred seventy-six".