217542489 has 16 divisors (see below), whose sum is σ = 310108032. Its totient is φ = 135168768.

The previous prime is 217542463. The next prime is 217542503. The reversal of 217542489 is 984245712.

It is not a de Polignac number, because 217542489 - 2⁷ = 217542361 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 217542489.

It is not an unprimeable number, because it can be changed into a prime (217542439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15454 + ... + 25959.

It is an arithmetic number, because the mean of its divisors is an integer number (19381752).

Almost surely, 2^217542489 is an apocalyptic number.

It is an amenable number.

217542489 is a deficient number, since it is larger than the sum of its proper divisors (92565543).

217542489 is a wasteful number, since it uses less digits than its factorization.

217542489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41536.

The product of its digits is 161280, while the sum is 42.

The square root of 217542489 is about 14749.3216454181. The cubic root of 217542489 is about 601.4248442419.

The spelling of 217542489 in words is "two hundred seventeen million, five hundred forty-two thousand, four hundred eighty-nine".