6661040 has 40 divisors (see below), whose sum is σ = 15789168. Its totient is φ = 2612480.

The previous prime is 6661037. The next prime is 6661049. The reversal of 6661040 is 401666.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 6660997 and 6661015.

It is not an unprimeable number, because it can be changed into a prime (6661049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3455 + ... + 5025.

Almost surely, 2^6661040 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 6661040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7894584).

6661040 is an abundant number, since it is smaller than the sum of its proper divisors (9128128).

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

6661040 is a wasteful number, since it uses less digits than its factorization.

6661040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1637 (or 1631 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 6661040 is about 2580.8990681544. The cubic root of 6661040 is about 188.1542419124.

The spelling of 6661040 in words is "six million, six hundred sixty-one thousand, forty".