6444864 has 84 divisors (see below), whose sum is σ = 18861024. Its totient is φ = 2103552.

The previous prime is 6444863. The next prime is 6444871. The reversal of 6444864 is 4684446.

6444864 is a `hidden beast` number, since 644 + 4 + 8 + 6 + 4 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is a d-powerful number, because it can be written as 6⁶ + 4⁹ + 4⁹ + 4¹⁰ + 8⁷ + 6⁸ + 4¹⁰ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6444863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38509 + ... + 38675.

It is an arithmetic number, because the mean of its divisors is an integer number (224536).

Almost surely, 2^6444864 is an apocalyptic number.

6444864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6444864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9430512).

6444864 is an abundant number, since it is smaller than the sum of its proper divisors (12416160).

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

6444864 is a wasteful number, since it uses less digits than its factorization.

6444864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252 (or 239 counting only the distinct ones).

The product of its digits is 73728, while the sum is 36.

The square root of 6444864 is about 2538.6736694581. The cubic root of 6444864 is about 186.0963773853.

The spelling of 6444864 in words is "six million, four hundred forty-four thousand, eight hundred sixty-four".