21020110103 has 4 divisors (see below), whose sum is σ = 21416716008. Its totient is φ = 20623504200.

The previous prime is 21020110091. The next prime is 21020110121. The reversal of 21020110103 is 30101102012.

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 21020110103 - 2⁴ = 21020110087 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 (21020110193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 198302873 + ... + 198302978.

It is an arithmetic number, because the mean of its divisors is an integer number (5354179002).

Almost surely, 2^21020110103 is an apocalyptic number.

21020110103 is a deficient number, since it is larger than the sum of its proper divisors (396605905).

21020110103 is an equidigital number, since it uses as much as digits as its factorization.

21020110103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396605904.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 21020110103 its reverse (30101102012), we get a palindrome (51121212115).

The spelling of 21020110103 in words is "twenty-one billion, twenty million, one hundred ten thousand, one hundred three".