21500235555203 has 4 divisors (see below), whose sum is σ = 21504289913808. Its totient is φ = 21496181196600.

The previous prime is 21500235555157. The next prime is 21500235555263. The reversal of 21500235555203 is 30255553200512.

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

It is a cyclic number.

It is not a de Polignac number, because 21500235555203 - 2¹⁰ = 21500235554179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21500235555263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2027171348 + ... + 2027181953.

It is an arithmetic number, because the mean of its divisors is an integer number (5376072478452).

Almost surely, 2^{21500235555203} is an apocalyptic number.

21500235555203 is a deficient number, since it is larger than the sum of its proper divisors (4054358605).

21500235555203 is an equidigital number, since it uses as much as digits as its factorization.

21500235555203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4054358604.

The product of its (nonzero) digits is 225000, while the sum is 38.

Adding to 21500235555203 its reverse (30255553200512), we get a palindrome (51755788755715).

The spelling of 21500235555203 in words is "twenty-one trillion, five hundred billion, two hundred thirty-five million, five hundred fifty-five thousand, two hundred three".