639407 has 8 divisors (see below), whose sum is σ = 683760. Its totient is φ = 596160.

The previous prime is 639391. The next prime is 639433. The reversal of 639407 is 704936.

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 639407 - 2⁴ = 639391 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639407.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639407.

It is not an unprimeable number, because it can be changed into a prime (639487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1157 + ... + 1617.

It is an arithmetic number, because the mean of its divisors is an integer number (85470).

2⁶³⁹⁴⁰⁷ is an apocalyptic number.

639407 is a deficient number, since it is larger than the sum of its proper divisors (44353).

639407 is a wasteful number, since it uses less digits than its factorization.

639407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 639407 is about 799.6292891084. The cubic root of 639407 is about 86.1507631313.

The spelling of 639407 in words is "six hundred thirty-nine thousand, four hundred seven".