1664403 has 8 divisors (see below), whose sum is σ = 2389968. Its totient is φ = 1024224.

The previous prime is 1664387. The next prime is 1664407. The reversal of 1664403 is 3044661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1664403 - 2⁴ = 1664387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1664407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21300 + ... + 21377.

It is an arithmetic number, because the mean of its divisors is an integer number (298746).

2^1664403 is an apocalyptic number.

1664403 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1664403 is a deficient number, since it is larger than the sum of its proper divisors (725565).

1664403 is a wasteful number, since it uses less digits than its factorization.

1664403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42693.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 1664403 is about 1290.1174365150. The cubic root of 1664403 is about 118.5094083577.

The spelling of 1664403 in words is "one million, six hundred sixty-four thousand, four hundred three".