12500081821 has 2 divisors, whose sum is σ = 12500081822. Its totient is φ = 12500081820.

The previous prime is 12500081819. The next prime is 12500081879. The reversal of 12500081821 is 12818000521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10235368900 + 2264712921 = 101170^2 + 47589^2 .

It is a cyclic number.

It is not a de Polignac number, because 12500081821 - 2¹ = 12500081819 is a prime.

Together with 12500081819, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 12500081821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12500081921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6250040910 + 6250040911.

It is an arithmetic number, because the mean of its divisors is an integer number (6250040911).

Almost surely, 2^12500081821 is an apocalyptic number.

It is an amenable number.

12500081821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12500081821 is an equidigital number, since it uses as much as digits as its factorization.

12500081821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1280, while the sum is 28.

The spelling of 12500081821 in words is "twelve billion, five hundred million, eighty-one thousand, eight hundred twenty-one".