21220065103 has 4 divisors (see below), whose sum is σ = 21227670928. Its totient is φ = 21212459280.

The previous prime is 21220065077. The next prime is 21220065133. The reversal of 21220065103 is 30156002212.

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-21220065103 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 (21220065133) 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, 3798726 + ... + 3804307.

It is an arithmetic number, because the mean of its divisors is an integer number (5306917732).

Almost surely, 2^21220065103 is an apocalyptic number.

21220065103 is a deficient number, since it is larger than the sum of its proper divisors (7605825).

21220065103 is an equidigital number, since it uses as much as digits as its factorization.

21220065103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7605824.

The product of its (nonzero) digits is 720, while the sum is 22.

Adding to 21220065103 its reverse (30156002212), we get a palindrome (51376067315).

The spelling of 21220065103 in words is "twenty-one billion, two hundred twenty million, sixty-five thousand, one hundred three".