639249 has 16 divisors (see below), whose sum is σ = 944832. Its totient is φ = 381888.

The previous prime is 639211. The next prime is 639253. The reversal of 639249 is 942936.

639249 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639249 - 2⁸ = 638993 is a prime.

639249 is strictly pandigital in base 7.

639249 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639249.

It is not an unprimeable number, because it can be changed into a prime (639259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1222 + ... + 1664.

It is an arithmetic number, because the mean of its divisors is an integer number (59052).

2⁶³⁹²⁴⁹ is an apocalyptic number.

It is an amenable number.

639249 is a deficient number, since it is larger than the sum of its proper divisors (305583).

639249 is a wasteful number, since it uses less digits than its factorization.

639249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496.

The product of its digits is 11664, while the sum is 33.

The square root of 639249 is about 799.5304872236. The cubic root of 639249 is about 86.1436664819.

It can be divided in two parts, 6392 and 49, that added together give a triangular number (6441 = T₁₁₃).

The spelling of 639249 in words is "six hundred thirty-nine thousand, two hundred forty-nine".