216788857 has 4 divisors (see below), whose sum is σ = 216860560. Its totient is φ = 216717156.

The previous prime is 216788851. The next prime is 216788867. The reversal of 216788857 is 758887612.

It is a happy number.

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 216788857 - 2⁷ = 216788729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216788851) 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, 31107 + ... + 37432.

It is an arithmetic number, because the mean of its divisors is an integer number (54215140).

Almost surely, 2^216788857 is an apocalyptic number.

It is an amenable number.

216788857 is a deficient number, since it is larger than the sum of its proper divisors (71703).

216788857 is an equidigital number, since it uses as much as digits as its factorization.

216788857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71702.

The product of its digits is 1505280, while the sum is 52.

The square root of 216788857 is about 14723.7514581033. The cubic root of 216788857 is about 600.7295357513.

The spelling of 216788857 in words is "two hundred sixteen million, seven hundred eighty-eight thousand, eight hundred fifty-seven".