6661872 has 80 divisors (see below), whose sum is σ = 21863680. Its totient is φ = 1902528.

The previous prime is 6661849. The next prime is 6661873. The reversal of 6661872 is 2781666.

It is a happy number.

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661873) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1923 + ... + 4125.

It is an arithmetic number, because the mean of its divisors is an integer number (273296).

Almost surely, 2^6661872 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 6661872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10931840).

6661872 is an abundant number, since it is smaller than the sum of its proper divisors (15201808).

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

6661872 is a wasteful number, since it uses less digits than its factorization.

6661872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2227 (or 2215 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 6661872 is about 2581.0602472627. The cubic root of 6661872 is about 188.1620754144.

The spelling of 6661872 in words is "six million, six hundred sixty-one thousand, eight hundred seventy-two".