666666395 has 8 divisors (see below), whose sum is σ = 842105040. Its totient is φ = 505262880.

The previous prime is 666666349. The next prime is 666666421. The reversal of 666666395 is 593666666.

It is a happy number.

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

It is not a de Polignac number, because 666666395 - 2¹⁴ = 666650011 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3508676 + ... + 3508865.

It is an arithmetic number, because the mean of its divisors is an integer number (105263130).

Almost surely, 2^666666395 is an apocalyptic number.

666666395 is a deficient number, since it is larger than the sum of its proper divisors (175438645).

666666395 is a wasteful number, since it uses less digits than its factorization.

666666395 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7017565.

The product of its digits is 6298560, while the sum is 53.

The square root of 666666395 is about 25819.8837139132. The cubic root of 666666395 is about 873.5803460749.

The spelling of 666666395 in words is "six hundred sixty-six million, six hundred sixty-six thousand, three hundred ninety-five".