21102112021 has 8 divisors (see below), whose sum is σ = 22193823744. Its totient is φ = 20036087760.

The previous prime is 21102112007. The next prime is 21102112039. The reversal of 21102112021 is 12021120112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21102112021 - 2¹⁹ = 21101587733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102111992 and 21102112010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102112001) 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 7 ways as a sum of consecutive naturals, for example, 6420181 + ... + 6423466.

It is an arithmetic number, because the mean of its divisors is an integer number (2774227968).

Almost surely, 2^21102112021 is an apocalyptic number.

It is an amenable number.

21102112021 is a deficient number, since it is larger than the sum of its proper divisors (1091711723).

21102112021 is a wasteful number, since it uses less digits than its factorization.

21102112021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12843731.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21102112021 its reverse (12021120112), we get a palindrome (33123232133).

The spelling of 21102112021 in words is "twenty-one billion, one hundred two million, one hundred twelve thousand, twenty-one".