216871885 has 4 divisors (see below), whose sum is σ = 260246268. Its totient is φ = 173497504.

The previous prime is 216871883. The next prime is 216871903. The reversal of 216871885 is 588178612.

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

It can be written as a sum of positive squares in 2 ways, for example, as 147549609 + 69322276 = 12147^2 + 8326^2 .

It is a cyclic number.

It is not a de Polignac number, because 216871885 - 2¹ = 216871883 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 (216871883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21687184 + ... + 21687193.

It is an arithmetic number, because the mean of its divisors is an integer number (65061567).

Almost surely, 2^216871885 is an apocalyptic number.

It is an amenable number.

216871885 is a deficient number, since it is larger than the sum of its proper divisors (43374383).

216871885 is an equidigital number, since it uses as much as digits as its factorization.

216871885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43374382.

The product of its digits is 215040, while the sum is 46.

The square root of 216871885 is about 14726.5707141887. The cubic root of 216871885 is about 600.8062171306.

The spelling of 216871885 in words is "two hundred sixteen million, eight hundred seventy-one thousand, eight hundred eighty-five".