216447289 has 2 divisors, whose sum is σ = 216447290. Its totient is φ = 216447288.

The previous prime is 216447269. The next prime is 216447293. The reversal of 216447289 is 982744612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192515625 + 23931664 = 13875^2 + 4892^2 .

It is a cyclic number.

It is not a de Polignac number, because 216447289 - 2⁹ = 216446777 is a prime.

It is not a weakly prime, because it can be changed into another prime (216447229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108223644 + 108223645.

It is an arithmetic number, because the mean of its divisors is an integer number (108223645).

Almost surely, 2^216447289 is an apocalyptic number.

It is an amenable number.

216447289 is a deficient number, since it is larger than the sum of its proper divisors (1).

216447289 is an equidigital number, since it uses as much as digits as its factorization.

216447289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 43.

The square root of 216447289 is about 14712.1476678288. The cubic root of 216447289 is about 600.4138709339.

The spelling of 216447289 in words is "two hundred sixteen million, four hundred forty-seven thousand, two hundred eighty-nine".