2661217705 has 4 divisors (see below), whose sum is σ = 3193461252. Its totient is φ = 2128974160.

The previous prime is 2661217697. The next prime is 2661217717. The reversal of 2661217705 is 5077121662.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5077121662 = 2 ⋅2538560831.

It can be written as a sum of positive squares in 2 ways, for example, as 913308841 + 1747908864 = 30221^2 + 41808^2 .

It is not a de Polignac number, because 2661217705 - 2³ = 2661217697 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 266121766 + ... + 266121775.

It is an arithmetic number, because the mean of its divisors is an integer number (798365313).

Almost surely, 2^2661217705 is an apocalyptic number.

It is an amenable number.

2661217705 is a deficient number, since it is larger than the sum of its proper divisors (532243547).

2661217705 is an equidigital number, since it uses as much as digits as its factorization.

2661217705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532243546.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 2661217705 is about 51586.9916257965. The cubic root of 2661217705 is about 1385.7773798838. Note that the first 3 decimals are identical.

The spelling of 2661217705 in words is "two billion, six hundred sixty-one million, two hundred seventeen thousand, seven hundred five".