12020021021 has 4 divisors (see below), whose sum is σ = 12344886492. Its totient is φ = 11695155552.

The previous prime is 12020021011. The next prime is 12020021047. The reversal of 12020021021 is 12012002021.

It is a happy number.

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 9552912121 + 2467108900 = 97739^2 + 49670^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12020021021 is a prime.

It is a super-3 number, since 3×12020021021³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12020020993 and 12020021011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12020021011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 162432680 + ... + 162432753.

It is an arithmetic number, because the mean of its divisors is an integer number (3086221623).

Almost surely, 2^12020021021 is an apocalyptic number.

It is an amenable number.

12020021021 is a deficient number, since it is larger than the sum of its proper divisors (324865471).

12020021021 is an equidigital number, since it uses as much as digits as its factorization.

12020021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324865470.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 12020021021 its reverse (12012002021), we get a palindrome (24032023042).

The spelling of 12020021021 in words is "twelve billion, twenty million, twenty-one thousand, twenty-one".