6666406655 has 8 divisors (see below), whose sum is σ = 8130830784. Its totient is φ = 5245696800.

The previous prime is 6666406651. The next prime is 6666406667. The reversal of 6666406655 is 5566046666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 6666406655 - 2² = 6666406651 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6666406651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10928231 + ... + 10928840.

It is an arithmetic number, because the mean of its divisors is an integer number (1016353848).

Almost surely, 2^6666406655 is an apocalyptic number.

6666406655 is a deficient number, since it is larger than the sum of its proper divisors (1464424129).

6666406655 is a wasteful number, since it uses less digits than its factorization.

6666406655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21857137.

The product of its (nonzero) digits is 4665600, while the sum is 50.

The square root of 6666406655 is about 81648.0658374710. The cubic root of 6666406655 is about 1882.0475894093.

The spelling of 6666406655 in words is "six billion, six hundred sixty-six million, four hundred six thousand, six hundred fifty-five".