12021612021 has 18 divisors (see below), whose sum is σ = 17846565282. Its totient is φ = 7797794400.

The previous prime is 12021611957. The next prime is 12021612049.

12021612021 is a `hidden beast` number, since 12 + 0 + 21 + 612 + 0 + 21 = 666.

12021612021 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 3 ways, for example, as 10152779121 + 1868832900 = 100761^2 + 43230^2 .

It is not a de Polignac number, because 12021612021 - 2⁶ = 12021611957 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12021611985 and 12021612003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12021692021) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 475530 + ... + 500171.

It is an arithmetic number, because the mean of its divisors is an integer number (991475849).

Almost surely, 2^12021612021 is an apocalyptic number.

It is an amenable number.

12021612021 is a deficient number, since it is larger than the sum of its proper divisors (5824953261).

12021612021 is an equidigital number, since it uses as much as digits as its factorization.

12021612021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 975781 (or 975741 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The spelling of 12021612021 in words is "twelve billion, twenty-one million, six hundred twelve thousand, twenty-one".