6440039 has 2 divisors, whose sum is σ = 6440040. Its totient is φ = 6440038.

The previous prime is 6440029. The next prime is 6440041. The reversal of 6440039 is 9300446.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6440039 - 2¹⁶ = 6374503 is a prime.

Together with 6440041, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6440029) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220019 + 3220020.

It is an arithmetic number, because the mean of its divisors is an integer number (3220020).

Almost surely, 2^6440039 is an apocalyptic number.

6440039 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440039 is an equidigital number, since it uses as much as digits as its factorization.

6440039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 6440039 is about 2537.7231921547. The cubic root of 6440039 is about 186.0499249341.

The spelling of 6440039 in words is "six million, four hundred forty thousand, thirty-nine".