6666659406 has 24 divisors (see below), whose sum is σ = 15757559064. Its totient is φ = 2020199760.

The previous prime is 6666659401. The next prime is 6666659437. The reversal of 6666659406 is 6049566666.

It is a happy number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6666659401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16834801 + ... + 16835196.

It is an arithmetic number, because the mean of its divisors is an integer number (656564961).

Almost surely, 2^6666659406 is an apocalyptic number.

6666659406 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

6666659406 is an abundant number, since it is smaller than the sum of its proper divisors (9090899658).

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

6666659406 is a wasteful number, since it uses less digits than its factorization.

6666659406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33670016 (or 33670013 counting only the distinct ones).

The product of its (nonzero) digits is 8398080, while the sum is 54.

The square root of 6666659406 is about 81649.6136304392. The cubic root of 6666659406 is about 1882.0713745069.

The spelling of 6666659406 in words is "six billion, six hundred sixty-six million, six hundred fifty-nine thousand, four hundred six".