6438739 has 8 divisors (see below), whose sum is σ = 6842000. Its totient is φ = 6041952.

The previous prime is 6438721. The next prime is 6438749. The reversal of 6438739 is 9378346.

6438739 = 187² + 188² + ... + 295².

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 6438739 - 2¹⁹ = 5914451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6438749) 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 7 ways as a sum of consecutive naturals, for example, 517 + ... + 3625.

It is an arithmetic number, because the mean of its divisors is an integer number (855250).

Almost surely, 2^6438739 is an apocalyptic number.

6438739 is a deficient number, since it is larger than the sum of its proper divisors (403261).

6438739 is a wasteful number, since it uses less digits than its factorization.

6438739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3237.

The product of its digits is 108864, while the sum is 40.

The square root of 6438739 is about 2537.4670441210. The cubic root of 6438739 is about 186.0374052802.

The spelling of 6438739 in words is "six million, four hundred thirty-eight thousand, seven hundred thirty-nine".