12010020021 has 12 divisors (see below), whose sum is σ = 17410437772. Its totient is φ = 7977773376.

The previous prime is 12010019993. The next prime is 12010020047. The reversal of 12010020021 is 12002001021.

It can be written as a sum of positive squares in 2 ways, for example, as 2930598225 + 9079421796 = 54135^2 + 95286^2 .

It is not a de Polignac number, because 12010020021 - 2¹⁹ = 12009495733 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12010019985 and 12010020012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12010022021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2406256 + ... + 2411241.

Almost surely, 2^12010020021 is an apocalyptic number.

It is an amenable number.

12010020021 is a deficient number, since it is larger than the sum of its proper divisors (5400417751).

12010020021 is a wasteful number, since it uses less digits than its factorization.

12010020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4817780 (or 4817777 counting only the distinct ones).

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

Adding to 12010020021 its reverse (12002001021), we get a palindrome (24012021042).

The spelling of 12010020021 in words is "twelve billion, ten million, twenty thousand, twenty-one".