216803857 has 4 divisors (see below), whose sum is σ = 217166400. Its totient is φ = 216441316.

The previous prime is 216803849. The next prime is 216803879. The reversal of 216803857 is 758308612.

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 216803857 - 2³ = 216803849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216873857) 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, 180373 + ... + 181570.

It is an arithmetic number, because the mean of its divisors is an integer number (54291600).

Almost surely, 2^216803857 is an apocalyptic number.

It is an amenable number.

216803857 is a deficient number, since it is larger than the sum of its proper divisors (362543).

216803857 is an equidigital number, since it uses as much as digits as its factorization.

216803857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362542.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 216803857 is about 14724.2608303439. The cubic root of 216803857 is about 600.7433906073.

The spelling of 216803857 in words is "two hundred sixteen million, eight hundred three thousand, eight hundred fifty-seven".