17218561 has 2 divisors, whose sum is σ = 17218562. Its totient is φ = 17218560.

The previous prime is 17218549. The next prime is 17218573. The reversal of 17218561 is 16581271.

It is a balanced prime because it is at equal distance from previous prime (17218549) and next prime (17218573).

It can be written as a sum of positive squares in only one way, i.e., 17139600 + 78961 = 4140^2 + 281^2 .

It is a cyclic number.

It is not a de Polignac number, because 17218561 - 2¹⁹ = 16694273 is a prime.

It is not a weakly prime, because it can be changed into another prime (17218261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8609280 + 8609281.

It is an arithmetic number, because the mean of its divisors is an integer number (8609281).

Almost surely, 2^17218561 is an apocalyptic number.

It is an amenable number.

17218561 is a deficient number, since it is larger than the sum of its proper divisors (1).

17218561 is an equidigital number, since it uses as much as digits as its factorization.

17218561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 31.

The square root of 17218561 is about 4149.5253945482. The cubic root of 17218561 is about 258.2253954437.

The spelling of 17218561 in words is "seventeen million, two hundred eighteen thousand, five hundred sixty-one".