1664889 has 16 divisors (see below), whose sum is σ = 2331072. Its totient is φ = 1055808.

The previous prime is 1664869. The next prime is 1664893. The reversal of 1664889 is 9884661.

It is not a de Polignac number, because 1664889 - 2⁵ = 1664857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1664889.

It is not an unprimeable number, because it can be changed into a prime (1664849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5742 + ... + 6024.

It is an arithmetic number, because the mean of its divisors is an integer number (145692).

2^1664889 is an apocalyptic number.

It is an amenable number.

1664889 is a deficient number, since it is larger than the sum of its proper divisors (666183).

1664889 is a wasteful number, since it uses less digits than its factorization.

1664889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376.

The product of its digits is 82944, while the sum is 42.

The square root of 1664889 is about 1290.3057777132. The cubic root of 1664889 is about 118.5209420162.

The spelling of 1664889 in words is "one million, six hundred sixty-four thousand, eight hundred eighty-nine".