21102110101 has 4 divisors (see below), whose sum is σ = 21829769100. Its totient is φ = 20374451104.

The previous prime is 21102110039. The next prime is 21102110123. The reversal of 21102110101 is 10101120112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 8947268100 + 12154842001 = 94590^2 + 110249^2 .

It is a cyclic number.

It is not a de Polignac number, because 21102110101 - 2²⁷ = 20967892373 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 (21102110171) 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, 363829456 + ... + 363829513.

It is an arithmetic number, because the mean of its divisors is an integer number (5457442275).

Almost surely, 2^21102110101 is an apocalyptic number.

It is an amenable number.

21102110101 is a deficient number, since it is larger than the sum of its proper divisors (727658999).

21102110101 is an equidigital number, since it uses as much as digits as its factorization.

21102110101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 727658998.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21102110101 its reverse (10101120112), we get a palindrome (31203230213).

It can be divided in two parts, 211021 and 10101, that added together give a palindrome (221122).

The spelling of 21102110101 in words is "twenty-one billion, one hundred two million, one hundred ten thousand, one hundred one".