639794 has 4 divisors (see below), whose sum is σ = 959694. Its totient is φ = 319896.

The previous prime is 639757. The next prime is 639833. The reversal of 639794 is 497936.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 469225 + 170569 = 685^2 + 413^2 .

It is a d-powerful number, because it can be written as 6⁶ + 3⁵ + 7⁴ + 9⁵ + 9⁶ + 4 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639794.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159947 + ... + 159950.

2⁶³⁹⁷⁹⁴ is an apocalyptic number.

639794 is a deficient number, since it is larger than the sum of its proper divisors (319900).

639794 is a wasteful number, since it uses less digits than its factorization.

639794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319899.

The product of its digits is 40824, while the sum is 38.

The square root of 639794 is about 799.8712396380. The cubic root of 639794 is about 86.1681404935.

The spelling of 639794 in words is "six hundred thirty-nine thousand, seven hundred ninety-four".