6399880 has 32 divisors (see below), whose sum is σ = 14491800. Its totient is φ = 2543616.

The previous prime is 6399859. The next prime is 6399889. The reversal of 6399880 is 889936.

It can be written as a sum of positive squares in 4 ways, for example, as 4588164 + 1811716 = 2142^2 + 1346^2 .

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (6399889) 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, 7306 + ... + 8134.

Almost surely, 2^6399880 is an apocalyptic number.

It is an amenable number.

6399880 is an abundant number, since it is smaller than the sum of its proper divisors (8091920).

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

6399880 is a wasteful number, since it uses less digits than its factorization.

6399880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1033 (or 1029 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 6399880 is about 2529.7984109411. The cubic root of 6399880 is about 185.6623929401.

The spelling of 6399880 in words is "six million, three hundred ninety-nine thousand, eight hundred eighty".