20663655503 has 4 divisors (see below), whose sum is σ = 20665098888. Its totient is φ = 20662212120.

The previous prime is 20663655497. The next prime is 20663655539. The reversal of 20663655503 is 30555636602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30555636602 = 2 ⋅15277818301.

It is a cyclic number.

It is not a de Polignac number, because 20663655503 - 2¹⁶ = 20663589967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20663655403) 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, 700001 + ... + 728922.

It is an arithmetic number, because the mean of its divisors is an integer number (5166274722).

Almost surely, 2^20663655503 is an apocalyptic number.

20663655503 is a deficient number, since it is larger than the sum of its proper divisors (1443385).

20663655503 is a wasteful number, since it uses less digits than its factorization.

20663655503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1443384.

The product of its (nonzero) digits is 486000, while the sum is 41.

The spelling of 20663655503 in words is "twenty billion, six hundred sixty-three million, six hundred fifty-five thousand, five hundred three".