216785663 has 4 divisors (see below), whose sum is σ = 217279920. Its totient is φ = 216291408.

The previous prime is 216785633. The next prime is 216785677. The reversal of 216785663 is 366587612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216785663 - 2¹⁰ = 216784639 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 (216785633) 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, 246470 + ... + 247347.

It is an arithmetic number, because the mean of its divisors is an integer number (54319980).

Almost surely, 2^216785663 is an apocalyptic number.

216785663 is a deficient number, since it is larger than the sum of its proper divisors (494257).

216785663 is an equidigital number, since it uses as much as digits as its factorization.

216785663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494256.

The product of its digits is 362880, while the sum is 44.

The square root of 216785663 is about 14723.6429934986. The cubic root of 216785663 is about 600.7265855081.

The spelling of 216785663 in words is "two hundred sixteen million, seven hundred eighty-five thousand, six hundred sixty-three".