6661375 has 32 divisors (see below), whose sum is σ = 9944064. Its totient is φ = 4356000.

The previous prime is 6661367. The next prime is 6661379. The reversal of 6661375 is 5731666.

It is a happy number.

It is not a de Polignac number, because 6661375 - 2³ = 6661367 is a prime.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

6661375 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6661375.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661379) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19960 + ... + 20290.

It is an arithmetic number, because the mean of its divisors is an integer number (310752).

Almost surely, 2^6661375 is an apocalyptic number.

6661375 is a deficient number, since it is larger than the sum of its proper divisors (3282689).

6661375 is a wasteful number, since it uses less digits than its factorization.

6661375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376 (or 366 counting only the distinct ones).

The product of its digits is 22680, while the sum is 34.

The square root of 6661375 is about 2580.9639672030. The cubic root of 6661375 is about 188.1573961052.

The spelling of 6661375 in words is "six million, six hundred sixty-one thousand, three hundred seventy-five".