2106666655 has 8 divisors (see below), whose sum is σ = 2531344032. Its totient is φ = 1683103968.

The previous prime is 2106666647. The next prime is 2106666671. The reversal of 2106666655 is 5566666012.

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

It is a cyclic number.

It is not a de Polignac number, because 2106666655 - 2³ = 2106666647 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 (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 274507 + ... + 282076.

It is an arithmetic number, because the mean of its divisors is an integer number (316418004).

Almost surely, 2^2106666655 is an apocalyptic number.

2106666655 is a deficient number, since it is larger than the sum of its proper divisors (424677377).

2106666655 is an equidigital number, since it uses as much as digits as its factorization.

2106666655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557345.

The product of its (nonzero) digits is 388800, while the sum is 43.

The square root of 2106666655 is about 45898.4384810638. The cubic root of 2106666655 is about 1281.9328413932.

The spelling of 2106666655 in words is "two billion, one hundred six million, six hundred sixty-six thousand, six hundred fifty-five".