12102100021 has 4 divisors (see below), whose sum is σ = 13202290944. Its totient is φ = 11001909100.

The previous prime is 12102100009. The next prime is 12102100037. The reversal of 12102100021 is 12000120121.

12102100021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12102100021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12102099980 and 12102100007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12102100081) 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, 550095445 + ... + 550095466.

It is an arithmetic number, because the mean of its divisors is an integer number (3300572736).

Almost surely, 2^12102100021 is an apocalyptic number.

12102100021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12102100021 is a deficient number, since it is larger than the sum of its proper divisors (1100190923).

12102100021 is a wasteful number, since it uses less digits than its factorization.

12102100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1100190922.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 12102100021 its reverse (12000120121), we get a palindrome (24102220142).

The spelling of 12102100021 in words is "twelve billion, one hundred two million, one hundred thousand, twenty-one".