21011023203 has 4 divisors (see below), whose sum is σ = 28014697608. Its totient is φ = 14007348800.

The previous prime is 21011023133. The next prime is 21011023211. The reversal of 21011023203 is 30232011012.

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 21011023203 - 2⁹ = 21011022691 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21011023223) 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 in 3 ways as a sum of consecutive naturals, for example, 3501837198 + ... + 3501837203.

It is an arithmetic number, because the mean of its divisors is an integer number (7003674402).

Almost surely, 2^21011023203 is an apocalyptic number.

21011023203 is a deficient number, since it is larger than the sum of its proper divisors (7003674405).

21011023203 is an equidigital number, since it uses as much as digits as its factorization.

21011023203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7003674404.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21011023203 its reverse (30232011012), we get a palindrome (51243034215).

The spelling of 21011023203 in words is "twenty-one billion, eleven million, twenty-three thousand, two hundred three".