216685853 has 4 divisors (see below), whose sum is σ = 217000128. Its totient is φ = 216371580.

The previous prime is 216685793. The next prime is 216685867. The reversal of 216685853 is 358586612.

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 216685853 - 2⁸ = 216685597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216681853) 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, 156101 + ... + 157482.

It is an arithmetic number, because the mean of its divisors is an integer number (54250032).

Almost surely, 2^216685853 is an apocalyptic number.

It is an amenable number.

216685853 is a deficient number, since it is larger than the sum of its proper divisors (314275).

216685853 is an equidigital number, since it uses as much as digits as its factorization.

216685853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314274.

The product of its digits is 345600, while the sum is 44.

The square root of 216685853 is about 14720.2531567905. The cubic root of 216685853 is about 600.6343781117.

The spelling of 216685853 in words is "two hundred sixteen million, six hundred eighty-five thousand, eight hundred fifty-three".