166403889 has 10 divisors (see below), whose sum is σ = 248578770. Its totient is φ = 110935872.

The previous prime is 166403857. The next prime is 166403917. The reversal of 166403889 is 988304661.

166403889 is a `hidden beast` number, since 166 + 403 + 8 + 89 = 666.

It can be written as a sum of positive squares in only one way, i.e., 83448225 + 82955664 = 9135^2 + 9108^2 .

It is not a de Polignac number, because 166403889 - 2⁵ = 166403857 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166403819) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1027104 + ... + 1027265.

It is an arithmetic number, because the mean of its divisors is an integer number (24857877).

Almost surely, 2^166403889 is an apocalyptic number.

It is an amenable number.

166403889 is a deficient number, since it is larger than the sum of its proper divisors (82174881).

166403889 is an equidigital number, since it uses as much as digits as its factorization.

166403889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2054381 (or 2054372 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 166403889 is about 12899.7631373603. The cubic root of 166403889 is about 550.0318317665.

The spelling of 166403889 in words is "one hundred sixty-six million, four hundred three thousand, eight hundred eighty-nine".