639499 has 12 divisors (see below), whose sum is σ = 769728. Its totient is φ = 529200.

The previous prime is 639493. The next prime is 639511. The reversal of 639499 is 994936.

It is not a de Polignac number, because 639499 - 2³ = 639491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (639491) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1309 + ... + 1729.

It is an arithmetic number, because the mean of its divisors is an integer number (64144).

2⁶³⁹⁴⁹⁹ is an apocalyptic number.

639499 is a deficient number, since it is larger than the sum of its proper divisors (130229).

639499 is a wasteful number, since it uses less digits than its factorization.

639499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466 (or 459 counting only the distinct ones).

The product of its digits is 52488, while the sum is 40.

The square root of 639499 is about 799.6868136965. The cubic root of 639499 is about 86.1548948190.

The spelling of 639499 in words is "six hundred thirty-nine thousand, four hundred ninety-nine".