6440239 has 16 divisors (see below), whose sum is σ = 7295904. Its totient is φ = 5644800.

The previous prime is 6440201. The next prime is 6440249. The reversal of 6440239 is 9320446.

It is a cyclic number.

It is not a de Polignac number, because 6440239 - 2¹¹ = 6438191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440249) 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 15 ways as a sum of consecutive naturals, for example, 22779 + ... + 23059.

It is an arithmetic number, because the mean of its divisors is an integer number (455994).

Almost surely, 2^6440239 is an apocalyptic number.

6440239 is a deficient number, since it is larger than the sum of its proper divisors (855665).

6440239 is a wasteful number, since it uses less digits than its factorization.

6440239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378.

The product of its (nonzero) digits is 5184, while the sum is 28.

The square root of 6440239 is about 2537.7625972498. The cubic root of 6440239 is about 186.0518508852.

The spelling of 6440239 in words is "six million, four hundred forty thousand, two hundred thirty-nine".