216863889 has 8 divisors (see below), whose sum is σ = 315438432. Its totient is φ = 131432640.

The previous prime is 216863887. The next prime is 216863909. The reversal of 216863889 is 988368612.

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

It is not a de Polignac number, because 216863889 - 2¹ = 216863887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216863887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3285784 + ... + 3285849.

It is an arithmetic number, because the mean of its divisors is an integer number (39429804).

Almost surely, 2^216863889 is an apocalyptic number.

It is an amenable number.

216863889 is a deficient number, since it is larger than the sum of its proper divisors (98574543).

216863889 is a wasteful number, since it uses less digits than its factorization.

216863889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6571647.

The product of its digits is 995328, while the sum is 51.

The square root of 216863889 is about 14726.2992296096. The cubic root of 216863889 is about 600.7988331928.

The spelling of 216863889 in words is "two hundred sixteen million, eight hundred sixty-three thousand, eight hundred eighty-nine".