12687544321 has 9 divisors (see below), whose sum is σ = 12872069379. Its totient is φ = 12505632336.

The previous prime is 12687544319. The next prime is 12687544327. The reversal of 12687544321 is 12344578621.

The square root of 12687544321 is 112639.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 7202068225 + 5485476096 = 84865^2 + 74064^2 .

It is not a de Polignac number, because 12687544321 - 2¹ = 12687544319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12687544327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8221876 + ... + 8223418.

It is an arithmetic number, because the mean of its divisors is an integer number (1430229931).

Almost surely, 2^12687544321 is an apocalyptic number.

12687544321 is the 112639-th square number.

12687544321 is the 56320-th centered octagonal number.

It is an amenable number.

12687544321 is a deficient number, since it is larger than the sum of its proper divisors (184525058).

12687544321 is an frugal number, since it uses more digits than its factorization.

12687544321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3232 (or 1616 counting only the distinct ones).

The product of its digits is 322560, while the sum is 43.

The spelling of 12687544321 in words is "twelve billion, six hundred eighty-seven million, five hundred forty-four thousand, three hundred twenty-one".