166648789 has 2 divisors, whose sum is σ = 166648790. Its totient is φ = 166648788.

The previous prime is 166648787. The next prime is 166648817. The reversal of 166648789 is 987846661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88679889 + 77968900 = 9417^2 + 8830^2 .

It is a cyclic number.

It is not a de Polignac number, because 166648789 - 2¹ = 166648787 is a prime.

Together with 166648787, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166648787) 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 as a sum of consecutive naturals, namely, 83324394 + 83324395.

It is an arithmetic number, because the mean of its divisors is an integer number (83324395).

Almost surely, 2^166648789 is an apocalyptic number.

It is an amenable number.

166648789 is a deficient number, since it is larger than the sum of its proper divisors (1).

166648789 is an equidigital number, since it uses as much as digits as its factorization.

166648789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3483648, while the sum is 55.

The square root of 166648789 is about 12909.2520697367. The cubic root of 166648789 is about 550.3015305273.

The spelling of 166648789 in words is "one hundred sixty-six million, six hundred forty-eight thousand, seven hundred eighty-nine".