6666438240 has 768 divisors, whose sum is σ = 29756160000. Its totient is φ = 1381847040.

The previous prime is 6666438223. The next prime is 6666438241. The reversal of 6666438240 is 428346666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6666438241) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 16299156 + ... + 16299564.

It is an arithmetic number, because the mean of its divisors is an integer number (38745000).

Almost surely, 2^6666438240 is an apocalyptic number.

6666438240 is a gapful number since it is divisible by the number (60) 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 6666438240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14878080000).

6666438240 is an abundant number, since it is smaller than the sum of its proper divisors (23089721760).

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

6666438240 is a wasteful number, since it uses less digits than its factorization.

6666438240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 465 (or 437 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 45.

The square root of 6666438240 is about 81648.2592588476. The cubic root of 6666438240 is about 1882.0505617442.

The spelling of 6666438240 in words is "six billion, six hundred sixty-six million, four hundred thirty-eight thousand, two hundred forty".