1666666055 has 8 divisors (see below), whose sum is σ = 2002856544. Its totient is φ = 1331428000.

The previous prime is 1666666049. The next prime is 1666666063. The reversal of 1666666055 is 5506666661.

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

It is not a de Polignac number, because 1666666055 - 2¹⁶ = 1666600519 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 234251 + ... + 241260.

It is an arithmetic number, because the mean of its divisors is an integer number (250357068).

Almost surely, 2^1666666055 is an apocalyptic number.

1666666055 is a deficient number, since it is larger than the sum of its proper divisors (336190489).

1666666055 is an equidigital number, since it uses as much as digits as its factorization.

1666666055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476217.

The product of its (nonzero) digits is 1166400, while the sum is 47.

The square root of 1666666055 is about 40824.8215550295. The cubic root of 1666666055 is about 1185.6309564545.

The spelling of 1666666055 in words is "one billion, six hundred sixty-six million, six hundred sixty-six thousand, fifty-five".