304639 has 4 divisors (see below), whose sum is σ = 305856. Its totient is φ = 303424.

The previous prime is 304631. The next prime is 304643. The reversal of 304639 is 936403.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 936403 = 13 ⋅72031.

It is a cyclic number.

It is not a de Polignac number, because 304639 - 2³ = 304631 is a prime.

It is a Duffinian number.

304639 is a lucky number.

It is a plaindrome in base 8.

It is a zygodrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (304631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79 + ... + 784.

It is an arithmetic number, because the mean of its divisors is an integer number (76464).

2³⁰⁴⁶³⁹ is an apocalyptic number.

304639 is a deficient number, since it is larger than the sum of its proper divisors (1217).

304639 is an equidigital number, since it uses as much as digits as its factorization.

304639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1216.

The product of its (nonzero) digits is 1944, while the sum is 25.

The square root of 304639 is about 551.9411200481. The cubic root of 304639 is about 67.2865870574.

The spelling of 304639 in words is "three hundred four thousand, six hundred thirty-nine".