2165666671 has 16 divisors (see below), whose sum is σ = 2527848000. Its totient is φ = 1854603744.

The previous prime is 2165666651. The next prime is 2165666681. The reversal of 2165666671 is 1766665612.

2165666671 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2165666671 - 2¹⁵ = 2165633903 is a prime.

It is a super-2 number, since 2×2165666671² = 9380224259760444482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165666621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 509985 + ... + 514213.

It is an arithmetic number, because the mean of its divisors is an integer number (157990500).

Almost surely, 2^2165666671 is an apocalyptic number.

2165666671 is a deficient number, since it is larger than the sum of its proper divisors (362181329).

2165666671 is an equidigital number, since it uses as much as digits as its factorization.

2165666671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5743 (or 5729 counting only the distinct ones).

The product of its digits is 544320, while the sum is 46.

The square root of 2165666671 is about 46536.7238962951. The cubic root of 2165666671 is about 1293.7902410535.

The spelling of 2165666671 in words is "two billion, one hundred sixty-five million, six hundred sixty-six thousand, six hundred seventy-one".