639047 has 4 divisors (see below), whose sum is σ = 676656. Its totient is φ = 601440.

The previous prime is 639043. The next prime is 639049. The reversal of 639047 is 740936.

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 639047 - 2² = 639043 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 12.

It is a nialpdrome in base 15.

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 639047.

It is not an unprimeable number, because it can be changed into a prime (639043) 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, 18779 + ... + 18812.

It is an arithmetic number, because the mean of its divisors is an integer number (169164).

2⁶³⁹⁰⁴⁷ is an apocalyptic number.

639047 is a deficient number, since it is larger than the sum of its proper divisors (37609).

639047 is a wasteful number, since it uses less digits than its factorization.

639047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37608.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 639047 is about 799.4041531040. The cubic root of 639047 is about 86.1345918470.

The spelling of 639047 in words is "six hundred thirty-nine thousand, forty-seven".