21531003103 has 4 divisors (see below), whose sum is σ = 21989109600. Its totient is φ = 21072896608.

The previous prime is 21531003077. The next prime is 21531003127. The reversal of 21531003103 is 30130013512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21531003103 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 (21531000103) 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, 229053178 + ... + 229053271.

It is an arithmetic number, because the mean of its divisors is an integer number (5497277400).

Almost surely, 2^21531003103 is an apocalyptic number.

21531003103 is a deficient number, since it is larger than the sum of its proper divisors (458106497).

21531003103 is an equidigital number, since it uses as much as digits as its factorization.

21531003103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458106496.

The product of its (nonzero) digits is 270, while the sum is 19.

Adding to 21531003103 its reverse (30130013512), we get a palindrome (51661016615).

The spelling of 21531003103 in words is "twenty-one billion, five hundred thirty-one million, three thousand, one hundred three".