1664445 has 16 divisors (see below), whose sum is σ = 2736000. Its totient is φ = 863424.

The previous prime is 1664437. The next prime is 1664447. The reversal of 1664445 is 5444661.

It is not a de Polignac number, because 1664445 - 2³ = 1664437 is a prime.

It is a Curzon number.

1664445 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664447) 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, 945 + ... + 2054.

It is an arithmetic number, because the mean of its divisors is an integer number (171000).

2^1664445 is an apocalyptic number.

1664445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1664445 is a deficient number, since it is larger than the sum of its proper divisors (1071555).

1664445 is a wasteful number, since it uses less digits than its factorization.

1664445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3044.

The product of its digits is 11520, while the sum is 30.

The square root of 1664445 is about 1290.1337140002. The cubic root of 1664445 is about 118.5104051822.

The spelling of 1664445 in words is "one million, six hundred sixty-four thousand, four hundred forty-five".