639288 has 48 divisors (see below), whose sum is σ = 1867320. Its totient is φ = 196416.

The previous prime is 639269. The next prime is 639299. The reversal of 639288 is 882936.

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

It is a nude number because it is divisible by every one of its digits.

It is a nialpdrome in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 595 + ... + 1277.

639288 is a Friedman number, since it can be written as 39*(8+2^(8+6)), using all its digits and the basic arithmetic operations.

2⁶³⁹²⁸⁸ 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 639288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (933660).

639288 is an abundant number, since it is smaller than the sum of its proper divisors (1228032).

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

639288 is a wasteful number, since it uses less digits than its factorization.

639288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708 (or 701 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 639288 is about 799.5548761655. The cubic root of 639288 is about 86.1454182952.

It can be divided in two parts, 63928 and 8, that added together give a palindrome (63936).

The spelling of 639288 in words is "six hundred thirty-nine thousand, two hundred eighty-eight".