216291243 has 18 divisors (see below), whose sum is σ = 335748924. Its totient is φ = 123493104.

The previous prime is 216291239. The next prime is 216291253. The reversal of 216291243 is 342192612.

It is not a de Polignac number, because 216291243 - 2² = 216291239 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 216291243.

It is not an unprimeable number, because it can be changed into a prime (216291203) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 177705 + ... + 178917.

It is an arithmetic number, because the mean of its divisors is an integer number (18652718).

Almost surely, 2^216291243 is an apocalyptic number.

216291243 is a deficient number, since it is larger than the sum of its proper divisors (119457681).

216291243 is an frugal number, since it uses more digits than its factorization.

216291243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2443 (or 1223 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 216291243 is about 14706.8434070673. The cubic root of 216291243 is about 600.2695483325.

The spelling of 216291243 in words is "two hundred sixteen million, two hundred ninety-one thousand, two hundred forty-three".