6399860 has 12 divisors (see below), whose sum is σ = 13439748. Its totient is φ = 2559936.

The previous prime is 6399859. The next prime is 6399889. The reversal of 6399860 is 689936.

It can be written as a sum of positive squares in 2 ways, for example, as 2910436 + 3489424 = 1706^2 + 1868^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159977 + ... + 160016.

It is an arithmetic number, because the mean of its divisors is an integer number (1119979).

Almost surely, 2^6399860 is an apocalyptic number.

It is an amenable number.

6399860 is an abundant number, since it is smaller than the sum of its proper divisors (7039888).

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

6399860 is a wasteful number, since it uses less digits than its factorization.

6399860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320002 (or 320000 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 6399860 is about 2529.7944580539. The cubic root of 6399860 is about 185.6621995379.

The spelling of 6399860 in words is "six million, three hundred ninety-nine thousand, eight hundred sixty".