1664738503 has 4 divisors (see below), whose sum is σ = 1683443520. Its totient is φ = 1646033488.

The previous prime is 1664738489. The next prime is 1664738531. The reversal of 1664738503 is 3058374661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3058374661 = 67 ⋅45647383.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1664738503 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1664738503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664738563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9352375 + ... + 9352552.

It is an arithmetic number, because the mean of its divisors is an integer number (420860880).

Almost surely, 2^1664738503 is an apocalyptic number.

1664738503 is a deficient number, since it is larger than the sum of its proper divisors (18705017).

1664738503 is an equidigital number, since it uses as much as digits as its factorization.

1664738503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18705016.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 1664738503 is about 40801.2071267506. The cubic root of 1664738503 is about 1185.1737069026.

The spelling of 1664738503 in words is "one billion, six hundred sixty-four million, seven hundred thirty-eight thousand, five hundred three".