1663003 has 4 divisors (see below), whose sum is σ = 1665648. Its totient is φ = 1660360.

The previous prime is 1662979. The next prime is 1663009. The reversal of 1663003 is 3003661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3003661 = 89 ⋅33749.

It is a cyclic number.

It is not a de Polignac number, because 1663003 - 2⁹ = 1662491 is a prime.

It is a Duffinian number.

1663003 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1663009) 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, 225 + ... + 1837.

It is an arithmetic number, because the mean of its divisors is an integer number (416412).

2^1663003 is an apocalyptic number.

1663003 is a deficient number, since it is larger than the sum of its proper divisors (2645).

1663003 is a wasteful number, since it uses less digits than its factorization.

1663003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2644.

The product of its (nonzero) digits is 324, while the sum is 19.

The square root of 1663003 is about 1289.5747361049. The cubic root of 1663003 is about 118.4761712726.

Adding to 1663003 its reverse (3003661), we get a palindrome (4666664).

The spelling of 1663003 in words is "one million, six hundred sixty-three thousand, three".