639814 has 16 divisors (see below), whose sum is σ = 1145088. Its totient is φ = 262152.

The previous prime is 639757. The next prime is 639833. The reversal of 639814 is 418936.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

639814 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 672 + ... + 1315.

It is an arithmetic number, because the mean of its divisors is an integer number (71568).

2⁶³⁹⁸¹⁴ is an apocalyptic number.

639814 is a deficient number, since it is larger than the sum of its proper divisors (505274).

639814 is a wasteful number, since it uses less digits than its factorization.

639814 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2019.

The product of its digits is 5184, while the sum is 31.

The square root of 639814 is about 799.8837415525. The cubic root of 639814 is about 86.1690383580.

The spelling of 639814 in words is "six hundred thirty-nine thousand, eight hundred fourteen".