639550 has 12 divisors (see below), whose sum is σ = 1189656. Its totient is φ = 255800.

The previous prime is 639547. The next prime is 639563. The reversal of 639550 is 55936.

It is a happy number.

639550 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6346 + ... + 6445.

It is an arithmetic number, because the mean of its divisors is an integer number (99138).

2⁶³⁹⁵⁵⁰ is an apocalyptic number.

639550 is a deficient number, since it is larger than the sum of its proper divisors (550106).

639550 is a wasteful number, since it uses less digits than its factorization.

639550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12803 (or 12798 counting only the distinct ones).

The product of its (nonzero) digits is 4050, while the sum is 28.

The square root of 639550 is about 799.7187005441. The cubic root of 639550 is about 86.1571850403.

The spelling of 639550 in words is "six hundred thirty-nine thousand, five hundred fifty".