6440659 has 4 divisors (see below), whose sum is σ = 6446016. Its totient is φ = 6435304.

The previous prime is 6440647. The next prime is 6440683. The reversal of 6440659 is 9560446.

6440659 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6440659 is a prime.

It is a super-3 number, since 3×6440659³ (a number of 21 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6440699) 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 3 ways as a sum of consecutive naturals, for example, 57 + ... + 3589.

It is an arithmetic number, because the mean of its divisors is an integer number (1611504).

Almost surely, 2^6440659 is an apocalyptic number.

6440659 is a deficient number, since it is larger than the sum of its proper divisors (5357).

6440659 is a wasteful number, since it uses less digits than its factorization.

6440659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5356.

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 6440659 is about 2537.8453459579. The cubic root of 6440659 is about 186.0558952526.

The spelling of 6440659 in words is "six million, four hundred forty thousand, six hundred fifty-nine".