6439668 has 24 divisors (see below), whose sum is σ = 15910272. Its totient is φ = 2020224.

The previous prime is 6439639. The next prime is 6439679. The reversal of 6439668 is 8669346.

It is a d-powerful number, because it can be written as 6³ + 4¹¹ + 3³ + 9⁶ + 6⁴ + 6⁸ + 8⁵ .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15580 + ... + 15987.

It is an arithmetic number, because the mean of its divisors is an integer number (662928).

Almost surely, 2^6439668 is an apocalyptic number.

6439668 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

6439668 is an abundant number, since it is smaller than the sum of its proper divisors (9470604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6439668 is a wasteful number, since it uses less digits than its factorization.

6439668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31591 (or 31589 counting only the distinct ones).

The product of its digits is 186624, while the sum is 42.

The square root of 6439668 is about 2537.6500940831. The cubic root of 6439668 is about 186.0463521893.

The spelling of 6439668 in words is "six million, four hundred thirty-nine thousand, six hundred sixty-eight".