12512021521 has 2 divisors, whose sum is σ = 12512021522. Its totient is φ = 12512021520.

The previous prime is 12512021513. The next prime is 12512021579.

It is a happy number.

12512021521 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12507290896 + 4730625 = 111836^2 + 2175^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 12512021521 - 2³ = 12512021513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12512021492 and 12512021501.

It is not a weakly prime, because it can be changed into another prime (12512021591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6256010760 + 6256010761.

It is an arithmetic number, because the mean of its divisors is an integer number (6256010761).

Almost surely, 2^12512021521 is an apocalyptic number.

It is an amenable number.

12512021521 is a deficient number, since it is larger than the sum of its proper divisors (1).

12512021521 is an equidigital number, since it uses as much as digits as its factorization.

12512021521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 22.

It can be divided in two parts, 125120 and 21521, that added together give a palindrome (146641).

The spelling of 12512021521 in words is "twelve billion, five hundred twelve million, twenty-one thousand, five hundred twenty-one".