6439998 has 16 divisors (see below), whose sum is σ = 13228560. Its totient is φ = 2088576.

The previous prime is 6439997. The next prime is 6440003. The reversal of 6439998 is 8999346.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6439997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14283 + ... + 14726.

It is an arithmetic number, because the mean of its divisors is an integer number (826785).

Almost surely, 2^6439998 is an apocalyptic number.

6439998 is an abundant number, since it is smaller than the sum of its proper divisors (6788562).

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

6439998 is a wasteful number, since it uses less digits than its factorization.

6439998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29051.

The product of its digits is 419904, while the sum is 48.

The square root of 6439998 is about 2537.7151140347. The cubic root of 6439998 is about 186.0495301092.

The spelling of 6439998 in words is "six million, four hundred thirty-nine thousand, nine hundred ninety-eight".