216545417 has 4 divisors (see below), whose sum is σ = 236231376. Its totient is φ = 196859460.

The previous prime is 216545401. The next prime is 216545431. The reversal of 216545417 is 714545612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216545417 - 2⁴ = 216545401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216544417) 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, 9842963 + ... + 9842984.

It is an arithmetic number, because the mean of its divisors is an integer number (59057844).

Almost surely, 2^216545417 is an apocalyptic number.

It is an amenable number.

216545417 is a deficient number, since it is larger than the sum of its proper divisors (19685959).

216545417 is a wasteful number, since it uses less digits than its factorization.

216545417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19685958.

The product of its digits is 33600, while the sum is 35.

The square root of 216545417 is about 14715.4822211166. The cubic root of 216545417 is about 600.5045912679.

The spelling of 216545417 in words is "two hundred sixteen million, five hundred forty-five thousand, four hundred seventeen".