216540847 has 4 divisors (see below), whose sum is σ = 216570640. Its totient is φ = 216511056.

The previous prime is 216540823. The next prime is 216540887. The reversal of 216540847 is 748045612.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 216540847 - 2⁷ = 216540719 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216540887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3979 + ... + 21187.

It is an arithmetic number, because the mean of its divisors is an integer number (54142660).

Almost surely, 2^216540847 is an apocalyptic number.

216540847 is a deficient number, since it is larger than the sum of its proper divisors (29793).

216540847 is a wasteful number, since it uses less digits than its factorization.

216540847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29792.

The product of its (nonzero) digits is 53760, while the sum is 37.

The square root of 216540847 is about 14715.3269416619. The cubic root of 216540847 is about 600.5003668649.

The spelling of 216540847 in words is "two hundred sixteen million, five hundred forty thousand, eight hundred forty-seven".