12100020021 has 36 divisors (see below), whose sum is σ = 19248229728. Its totient is φ = 7309806768.

The previous prime is 12100019947. The next prime is 12100020029. The reversal of 12100020021 is 12002000121.

It is not a de Polignac number, because 12100020021 - 2⁹ = 12100019509 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 12100019985 and 12100020012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12100020029) 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 35 ways as a sum of consecutive naturals, for example, 6235 + ... + 155688.

It is an arithmetic number, because the mean of its divisors is an integer number (534673048).

Almost surely, 2^12100020021 is an apocalyptic number.

It is an amenable number.

12100020021 is a deficient number, since it is larger than the sum of its proper divisors (7148209707).

12100020021 is a wasteful number, since it uses less digits than its factorization.

12100020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161990 (or 161968 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 12100020021 its reverse (12002000121), we get a palindrome (24102020142).

The spelling of 12100020021 in words is "twelve billion, one hundred million, twenty thousand, twenty-one".