389666561 has 2 divisors, whose sum is σ = 389666562. Its totient is φ = 389666560.

The previous prime is 389666539. The next prime is 389666579. The reversal of 389666561 is 165666983.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 301682161 + 87984400 = 17369^2 + 9380^2 .

It is an emirp because it is prime and its reverse (165666983) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 389666561 - 2¹⁸ = 389404417 is a prime.

It is not a weakly prime, because it can be changed into another prime (389666521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 194833280 + 194833281.

It is an arithmetic number, because the mean of its divisors is an integer number (194833281).

Almost surely, 2^389666561 is an apocalyptic number.

It is an amenable number.

389666561 is a deficient number, since it is larger than the sum of its proper divisors (1).

389666561 is an equidigital number, since it uses as much as digits as its factorization.

389666561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 50.

The square root of 389666561 is about 19739.9736828599. The cubic root of 389666561 is about 730.4060798150.

The spelling of 389666561 in words is "three hundred eighty-nine million, six hundred sixty-six thousand, five hundred sixty-one".