217352561 has 2 divisors, whose sum is σ = 217352562. Its totient is φ = 217352560.

The previous prime is 217352543. The next prime is 217352579. The reversal of 217352561 is 165253712.

217352561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (217352543) and next prime (217352579).

It can be written as a sum of positive squares in only one way, i.e., 171112561 + 46240000 = 13081^2 + 6800^2 .

It is a cyclic number.

It is not a de Polignac number, because 217352561 - 2¹⁸ = 217090417 is a prime.

It is not a weakly prime, because it can be changed into another prime (217354561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108676280 + 108676281.

It is an arithmetic number, because the mean of its divisors is an integer number (108676281).

Almost surely, 2^217352561 is an apocalyptic number.

It is an amenable number.

217352561 is a deficient number, since it is larger than the sum of its proper divisors (1).

217352561 is an equidigital number, since it uses as much as digits as its factorization.

217352561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12600, while the sum is 32.

The square root of 217352561 is about 14742.8817060980. The cubic root of 217352561 is about 601.2497662959.

The spelling of 217352561 in words is "two hundred seventeen million, three hundred fifty-two thousand, five hundred sixty-one".