6391880 has 64 divisors (see below), whose sum is σ = 15984000. Its totient is φ = 2280960.

The previous prime is 6391877. The next prime is 6391897. The reversal of 6391880 is 881936.

It is a super-2 number, since 2×6391880² = 81712259868800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6391880.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32021 + ... + 32219.

It is an arithmetic number, because the mean of its divisors is an integer number (249750).

Almost surely, 2^6391880 is an apocalyptic number.

6391880 is the 1460-th octagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6391880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7992000).

6391880 is an abundant number, since it is smaller than the sum of its proper divisors (9592120).

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

6391880 is a wasteful number, since it uses less digits than its factorization.

6391880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 6391880 is about 2528.2167628588. The cubic root of 6391880 is about 185.5849999025.

The spelling of 6391880 in words is "six million, three hundred ninety-one thousand, eight hundred eighty".