639683 has 4 divisors (see below), whose sum is σ = 697848. Its totient is φ = 581520.

The previous prime is 639679. The next prime is 639689. The reversal of 639683 is 386936.

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 639683 - 2² = 639679 is a prime.

It is a d-powerful number, because it can be written as 6⁴ + 3¹⁰ + 6⁶ + 9³ + 8³ + 3¹² .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639689) 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, 29066 + ... + 29087.

It is an arithmetic number, because the mean of its divisors is an integer number (174462).

2⁶³⁹⁶⁸³ is an apocalyptic number.

639683 is a deficient number, since it is larger than the sum of its proper divisors (58165).

639683 is a wasteful number, since it uses less digits than its factorization.

639683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58164.

The product of its digits is 23328, while the sum is 35.

The square root of 639683 is about 799.8018504605. The cubic root of 639683 is about 86.1631570057.

The spelling of 639683 in words is "six hundred thirty-nine thousand, six hundred eighty-three".