166216665 has 16 divisors (see below), whose sum is σ = 272434176. Its totient is φ = 86486400.

The previous prime is 166216651. The next prime is 166216679. The reversal of 166216665 is 566612661.

166216665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (166216651) and next prime (166216679).

It is not a de Polignac number, because 166216665 - 2⁶ = 166216601 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 134521 + ... + 135750.

It is an arithmetic number, because the mean of its divisors is an integer number (17027136).

Almost surely, 2^166216665 is an apocalyptic number.

166216665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166216665 is a deficient number, since it is larger than the sum of its proper divisors (106217511).

166216665 is a wasteful number, since it uses less digits than its factorization.

166216665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270320.

The product of its digits is 77760, while the sum is 39.

The square root of 166216665 is about 12892.5042175677. The cubic root of 166216665 is about 549.8254707940.

The spelling of 166216665 in words is "one hundred sixty-six million, two hundred sixteen thousand, six hundred sixty-five".