21506103326203 has 6 divisors (see below), whose sum is σ = 21831880792596. Its totient is φ = 21185116704972.

The previous prime is 21506103326173. The next prime is 21506103326209. The reversal of 21506103326203 is 30262330160512.

It is a de Polignac number, because none of the positive numbers 2^k-21506103326203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21506103326209) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2395418025 + ... + 2395427002.

It is an arithmetic number, because the mean of its divisors is an integer number (3638646798766).

Almost surely, 2^{21506103326203} is an apocalyptic number.

21506103326203 is a deficient number, since it is larger than the sum of its proper divisors (325777466393).

21506103326203 is an frugal number, since it uses more digits than its factorization.

21506103326203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4790845161 (or 4790845094 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 34.

Adding to 21506103326203 its reverse (30262330160512), we get a palindrome (51768433486715).

The spelling of 21506103326203 in words is "twenty-one trillion, five hundred six billion, one hundred three million, three hundred twenty-six thousand, two hundred three".