216855589 has 2 divisors, whose sum is σ = 216855590. Its totient is φ = 216855588.

The previous prime is 216855559. The next prime is 216855593. The reversal of 216855589 is 985558612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197627364 + 19228225 = 14058^2 + 4385^2 .

It is a cyclic number.

It is not a de Polignac number, because 216855589 - 2¹¹ = 216853541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216855539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108427794 + 108427795.

It is an arithmetic number, because the mean of its divisors is an integer number (108427795).

Almost surely, 2^216855589 is an apocalyptic number.

It is an amenable number.

216855589 is a deficient number, since it is larger than the sum of its proper divisors (1).

216855589 is an equidigital number, since it uses as much as digits as its factorization.

216855589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864000, while the sum is 49.

The square root of 216855589 is about 14726.0174181616. The cubic root of 216855589 is about 600.7911683329.

The spelling of 216855589 in words is "two hundred sixteen million, eight hundred fifty-five thousand, five hundred eighty-nine".