216716665 has 8 divisors (see below), whose sum is σ = 283701888. Its totient is φ = 157612080.

The previous prime is 216716657. The next prime is 216716683. The reversal of 216716665 is 566617612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216716665 - 2³ = 216716657 is a prime.

It is a super-2 number, since 2×216716665² = 93932225777444450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1970097 + ... + 1970206.

It is an arithmetic number, because the mean of its divisors is an integer number (35462736).

Almost surely, 2^216716665 is an apocalyptic number.

It is an amenable number.

216716665 is a deficient number, since it is larger than the sum of its proper divisors (66985223).

216716665 is a wasteful number, since it uses less digits than its factorization.

216716665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3940319.

The product of its digits is 90720, while the sum is 40.

The square root of 216716665 is about 14721.2997048494. The cubic root of 216716665 is about 600.6628461590.

The spelling of 216716665 in words is "two hundred sixteen million, seven hundred sixteen thousand, six hundred sixty-five".