639763 has 4 divisors (see below), whose sum is σ = 651888. Its totient is φ = 627640.

The previous prime is 639757. The next prime is 639833. The reversal of 639763 is 367936.

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 639763 - 2⁵ = 639731 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639703) 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, 5983 + ... + 6088.

It is an arithmetic number, because the mean of its divisors is an integer number (162972).

2⁶³⁹⁷⁶³ is an apocalyptic number.

639763 is a deficient number, since it is larger than the sum of its proper divisors (12125).

639763 is a wasteful number, since it uses less digits than its factorization.

639763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12124.

The product of its digits is 20412, while the sum is 34.

The square root of 639763 is about 799.8518612843. The cubic root of 639763 is about 86.1667487667.

The spelling of 639763 in words is "six hundred thirty-nine thousand, seven hundred sixty-three".