6391872 has 98 divisors (see below), whose sum is σ = 19155918. Its totient is φ = 2115072.

The previous prime is 6391841. The next prime is 6391877. The reversal of 6391872 is 2781936.

6391872 is a `hidden beast` number, since 639 + 18 + 7 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5645376 + 746496 = 2376^2 + 864^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6391877) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 46588 + ... + 46724.

Almost surely, 2^6391872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6391872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9577959).

6391872 is an abundant number, since it is smaller than the sum of its proper divisors (12764046).

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

6391872 is an equidigital number, since it uses as much as digits as its factorization.

6391872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 142 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 6391872 is about 2528.2151807154. The cubic root of 6391872 is about 185.5849224771.

The spelling of 6391872 in words is "six million, three hundred ninety-one thousand, eight hundred seventy-two".