216665515 has 8 divisors (see below), whose sum is σ = 283634928. Its totient is φ = 157574880.

The previous prime is 216665509. The next prime is 216665551. The reversal of 216665515 is 515566612.

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

It is not a de Polignac number, because 216665515 - 2¹⁵ = 216632747 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1969632 + ... + 1969741.

It is an arithmetic number, because the mean of its divisors is an integer number (35454366).

Almost surely, 2^216665515 is an apocalyptic number.

216665515 is a deficient number, since it is larger than the sum of its proper divisors (66969413).

216665515 is a wasteful number, since it uses less digits than its factorization.

216665515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3939389.

The product of its digits is 54000, while the sum is 37.

The square root of 216665515 is about 14719.5623236562. The cubic root of 216665515 is about 600.6155858001.

The spelling of 216665515 in words is "two hundred sixteen million, six hundred sixty-five thousand, five hundred fifteen".