2166257717 has 6 divisors (see below), whose sum is σ = 2345711202. Its totient is φ = 1999622352.

The previous prime is 2166257707. The next prime is 2166257791. The reversal of 2166257717 is 7177526612.

It can be written as a sum of positive squares in 3 ways, for example, as 844561 + 2165413156 = 919^2 + 46534^2 .

It is not a de Polignac number, because 2166257717 - 2¹⁰ = 2166256693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2166257707) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6408878 + ... + 6409215.

It is an arithmetic number, because the mean of its divisors is an integer number (390951867).

Almost surely, 2^2166257717 is an apocalyptic number.

It is an amenable number.

2166257717 is a deficient number, since it is larger than the sum of its proper divisors (179453485).

2166257717 is a wasteful number, since it uses less digits than its factorization.

2166257717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12818119 (or 12818106 counting only the distinct ones).

The product of its digits is 246960, while the sum is 44.

The square root of 2166257717 is about 46543.0737811761. The cubic root of 2166257717 is about 1293.9079292158.

The spelling of 2166257717 in words is "two billion, one hundred sixty-six million, two hundred fifty-seven thousand, seven hundred seventeen".