21531054203 has 2 divisors, whose sum is σ = 21531054204. Its totient is φ = 21531054202.

The previous prime is 21531054157. The next prime is 21531054241. The reversal of 21531054203 is 30245013512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21531054203 - 2¹⁴ = 21531037819 is a prime.

It is not a weakly prime, because it can be changed into another prime (21531056203) 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 as a sum of consecutive naturals, namely, 10765527101 + 10765527102.

It is an arithmetic number, because the mean of its divisors is an integer number (10765527102).

Almost surely, 2^21531054203 is an apocalyptic number.

21531054203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21531054203 is an equidigital number, since it uses as much as digits as its factorization.

21531054203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21531054203 its reverse (30245013512), we get a palindrome (51776067715).

The spelling of 21531054203 in words is "twenty-one billion, five hundred thirty-one million, fifty-four thousand, two hundred three".