216987 has 8 divisors (see below), whose sum is σ = 291840. Its totient is φ = 143400.

The previous prime is 216973. The next prime is 216991. The reversal of 216987 is 789612.

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

It is not a de Polignac number, because 216987 - 2⁷ = 216859 is a prime.

It is an alternating number because its digits alternate between even and odd.

216987 is a lucky number.

It is a plaindrome in base 15.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216987.

It is not an unprimeable number, because it can be changed into a prime (216917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 214 + ... + 692.

It is an arithmetic number, because the mean of its divisors is an integer number (36480).

2²¹⁶⁹⁸⁷ is an apocalyptic number.

216987 is a deficient number, since it is larger than the sum of its proper divisors (74853).

216987 is a wasteful number, since it uses less digits than its factorization.

216987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633.

The product of its digits is 6048, while the sum is 33.

The square root of 216987 is about 465.8186342344. The cubic root of 216987 is about 60.0912500424.

The spelling of 216987 in words is "two hundred sixteen thousand, nine hundred eighty-seven".