6439889 has 4 divisors (see below), whose sum is σ = 6818724. Its totient is φ = 6061056.

The previous prime is 6439837. The next prime is 6439903. The reversal of 6439889 is 9889346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2371600 + 4068289 = 1540^2 + 2017^2 .

It is a cyclic number.

It is not a de Polignac number, because 6439889 - 2¹⁶ = 6374353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6439819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 189392 + ... + 189425.

It is an arithmetic number, because the mean of its divisors is an integer number (1704681).

Almost surely, 2^6439889 is an apocalyptic number.

It is an amenable number.

6439889 is a deficient number, since it is larger than the sum of its proper divisors (378835).

6439889 is a wasteful number, since it uses less digits than its factorization.

6439889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378834.

The product of its digits is 373248, while the sum is 47.

The square root of 6439889 is about 2537.6936379319. The cubic root of 6439889 is about 186.0484804446.

The spelling of 6439889 in words is "six million, four hundred thirty-nine thousand, eight hundred eighty-nine".