2666166605 has 4 divisors (see below), whose sum is σ = 3199399932. Its totient is φ = 2132933280.

The previous prime is 2666166571. The next prime is 2666166617. The reversal of 2666166605 is 5066616662.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5066616662 = 2 ⋅2533308331.

It can be written as a sum of positive squares in 2 ways, for example, as 1977314089 + 688852516 = 44467^2 + 26246^2 .

It is not a de Polignac number, because 2666166605 - 2¹⁶ = 2666101069 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 3 ways as a sum of consecutive naturals, for example, 266616656 + ... + 266616665.

It is an arithmetic number, because the mean of its divisors is an integer number (799849983).

Almost surely, 2^2666166605 is an apocalyptic number.

It is an amenable number.

2666166605 is a deficient number, since it is larger than the sum of its proper divisors (533233327).

2666166605 is an equidigital number, since it uses as much as digits as its factorization.

2666166605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533233326.

The product of its (nonzero) digits is 466560, while the sum is 44.

The square root of 2666166605 is about 51634.9358961546. The cubic root of 2666166605 is about 1386.6358624339.

The spelling of 2666166605 in words is "two billion, six hundred sixty-six million, one hundred sixty-six thousand, six hundred five".