21121013103 has 4 divisors (see below), whose sum is σ = 28161350808. Its totient is φ = 14080675400.

The previous prime is 21121013099. The next prime is 21121013119. The reversal of 21121013103 is 30131012112.

It is a happy number.

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 21121013103 - 2² = 21121013099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121013143) 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, 3520168848 + ... + 3520168853.

It is an arithmetic number, because the mean of its divisors is an integer number (7040337702).

Almost surely, 2^21121013103 is an apocalyptic number.

21121013103 is a deficient number, since it is larger than the sum of its proper divisors (7040337705).

21121013103 is an equidigital number, since it uses as much as digits as its factorization.

21121013103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7040337704.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21121013103 its reverse (30131012112), we get a palindrome (51252025215).

Subtracting 21121013103 from its reverse (30131012112), we obtain a palindrome (9009999009).

The spelling of 21121013103 in words is "twenty-one billion, one hundred twenty-one million, thirteen thousand, one hundred three".