639379 has 8 divisors (see below), whose sum is σ = 695520. Its totient is φ = 584256.

The previous prime is 639371. The next prime is 639391. The reversal of 639379 is 973936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 639379 - 2³ = 639371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639371) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1602 + ... + 1960.

It is an arithmetic number, because the mean of its divisors is an integer number (86940).

2⁶³⁹³⁷⁹ is an apocalyptic number.

639379 is a deficient number, since it is larger than the sum of its proper divisors (56141).

639379 is a wasteful number, since it uses less digits than its factorization.

639379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 509.

The product of its digits is 30618, while the sum is 37.

The square root of 639379 is about 799.6117808037. The cubic root of 639379 is about 86.1495055824.

The spelling of 639379 in words is "six hundred thirty-nine thousand, three hundred seventy-nine".