166888889 has 2 divisors, whose sum is σ = 166888890. Its totient is φ = 166888888.

The previous prime is 166888873. The next prime is 166888921. The reversal of 166888889 is 988888661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166848889 + 40000 = 12917^2 + 200^2 .

It is a cyclic number.

It is not a de Polignac number, because 166888889 - 2⁴ = 166888873 is a prime.

It is a plaindrome in base 10.

It is not a weakly prime, because it can be changed into another prime (166888829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83444444 + 83444445.

It is an arithmetic number, because the mean of its divisors is an integer number (83444445).

Almost surely, 2^166888889 is an apocalyptic number.

It is an amenable number.

166888889 is a deficient number, since it is larger than the sum of its proper divisors (1).

166888889 is an equidigital number, since it uses as much as digits as its factorization.

166888889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10616832, while the sum is 62.

The square root of 166888889 is about 12918.5482543512. The cubic root of 166888889 is about 550.5656868499.

The spelling of 166888889 in words is "one hundred sixty-six million, eight hundred eighty-eight thousand, eight hundred eighty-nine".