6665540 has 48 divisors (see below), whose sum is σ = 16353792. Its totient is φ = 2234496.

The previous prime is 6665539. The next prime is 6665567. The reversal of 6665540 is 455666.

6665540 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is an Ulam number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 6665497 and 6665506.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 6074 + ... + 7086.

It is an arithmetic number, because the mean of its divisors is an integer number (340704).

Almost surely, 2^6665540 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 6665540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8176896).

6665540 is an abundant number, since it is smaller than the sum of its proper divisors (9688252).

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

6665540 is a wasteful number, since it uses less digits than its factorization.

6665540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076 (or 1074 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 6665540 is about 2581.7707101910. The cubic root of 6665540 is about 188.1966028396.

The spelling of 6665540 in words is "six million, six hundred sixty-five thousand, five hundred forty".