216666671 has 16 divisors (see below), whose sum is σ = 246153600. Its totient is φ = 189057888.

The previous prime is 216666661. The next prime is 216666691. The reversal of 216666671 is 176666612.

216666671 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 216666671 - 2⁶ = 216666607 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 (216666631) 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, 181940 + ... + 183126.

It is an arithmetic number, because the mean of its divisors is an integer number (15384600).

Almost surely, 2^216666671 is an apocalyptic number.

216666671 is a deficient number, since it is larger than the sum of its proper divisors (29486929).

216666671 is a wasteful number, since it uses less digits than its factorization.

216666671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1958.

The product of its digits is 108864, while the sum is 41.

The square root of 216666671 is about 14719.6015910758. The cubic root of 216666671 is about 600.6166539756.

The spelling of 216666671 in words is "two hundred sixteen million, six hundred sixty-six thousand, six hundred seventy-one".