639071 has 4 divisors (see below), whose sum is σ = 648144. Its totient is φ = 630000.

The previous prime is 639053. The next prime is 639083. The reversal of 639071 is 170936.

It is a happy number.

639071 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 639071 - 2⁶ = 639007 is a prime.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 639071.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639011) 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, 4430 + ... + 4571.

It is an arithmetic number, because the mean of its divisors is an integer number (162036).

2⁶³⁹⁰⁷¹ is an apocalyptic number.

639071 is a deficient number, since it is larger than the sum of its proper divisors (9073).

639071 is an equidigital number, since it uses as much as digits as its factorization.

639071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9072.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 639071 is about 799.4191641436. The cubic root of 639071 is about 86.1356701215.

The spelling of 639071 in words is "six hundred thirty-nine thousand, seventy-one".