216666907 has 4 divisors (see below), whose sum is σ = 217449376. Its totient is φ = 215884440.

The previous prime is 216666893. The next prime is 216666941. The reversal of 216666907 is 709666612.

216666907 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216666907 - 2²³ = 208278299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216666977) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 390819 + ... + 391372.

It is an arithmetic number, because the mean of its divisors is an integer number (54362344).

Almost surely, 2^216666907 is an apocalyptic number.

216666907 is a deficient number, since it is larger than the sum of its proper divisors (782469).

216666907 is an equidigital number, since it uses as much as digits as its factorization.

216666907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782468.

The product of its (nonzero) digits is 163296, while the sum is 43.

The square root of 216666907 is about 14719.6096075949. The cubic root of 216666907 is about 600.6168720456.

The spelling of 216666907 in words is "two hundred sixteen million, six hundred sixty-six thousand, nine hundred seven".