1664003 has 4 divisors (see below), whose sum is σ = 1815288. Its totient is φ = 1512720.

The previous prime is 1663997. The next prime is 1664009. The reversal of 1664003 is 3004661.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1663997) and next prime (1664009).

It is not a de Polignac number, because 1664003 - 2⁸ = 1663747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1664009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75626 + ... + 75647.

It is an arithmetic number, because the mean of its divisors is an integer number (453822).

2^1664003 is an apocalyptic number.

1664003 is a deficient number, since it is larger than the sum of its proper divisors (151285).

1664003 is a wasteful number, since it uses less digits than its factorization.

1664003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151284.

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 1664003 is about 1289.9624025529. The cubic root of 1664003 is about 118.4999139501.

Adding to 1664003 its reverse (3004661), we get a palindrome (4668664).

The spelling of 1664003 in words is "one million, six hundred sixty-four thousand, three".