12012621021 has 24 divisors (see below), whose sum is σ = 17884082424. Its totient is φ = 7764180480.

The previous prime is 12012621011. The next prime is 12012621029.

12012621021 is a `hidden beast` number, since 1 + 20 + 1 + 2 + 621 + 0 + 21 = 666.

12012621021 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 5858218521 + 6154402500 = 76539^2 + 78450^2 .

It is not a de Polignac number, because 12012621021 - 2⁹ = 12012620509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12012620985 and 12012621003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12012621029) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29385 + ... + 157761.

It is an arithmetic number, because the mean of its divisors is an integer number (745170101).

Almost surely, 2^12012621021 is an apocalyptic number.

It is an amenable number.

12012621021 is a deficient number, since it is larger than the sum of its proper divisors (5871461403).

12012621021 is a wasteful number, since it uses less digits than its factorization.

12012621021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128701 (or 128698 counting only the distinct ones).

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

The spelling of 12012621021 in words is "twelve billion, twelve million, six hundred twenty-one thousand, twenty-one".