216985287 has 8 divisors (see below), whose sum is σ = 289656304. Its totient is φ = 144485568.

The previous prime is 216985283. The next prime is 216985309. The reversal of 216985287 is 782589612.

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

It is not a de Polignac number, because 216985287 - 2² = 216985283 is a prime.

It is a super-2 number, since 2×216985287² = 94165229548944738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216985283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39838 + ... + 44955.

It is an arithmetic number, because the mean of its divisors is an integer number (36207038).

Almost surely, 2^216985287 is an apocalyptic number.

216985287 is a deficient number, since it is larger than the sum of its proper divisors (72671017).

216985287 is an equidigital number, since it uses as much as digits as its factorization.

216985287 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85649.

The product of its digits is 483840, while the sum is 48.

The square root of 216985287 is about 14730.4204624308. The cubic root of 216985287 is about 600.9109191218.

The spelling of 216985287 in words is "two hundred sixteen million, nine hundred eighty-five thousand, two hundred eighty-seven".