12156582321 has 24 divisors (see below), whose sum is σ = 18915809640. Its totient is φ = 7478770176.

The previous prime is 12156582293. The next prime is 12156582359. The reversal of 12156582321 is 12328565121.

12156582321 is a `hidden beast` number, since 1 + 2 + 1 + 56 + 582 + 3 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 281031696 + 11875550625 = 16764^2 + 108975^2 .

It is not a de Polignac number, because 12156582321 - 2⁹ = 12156581809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12156582391) 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, 441655 + ... + 468371.

It is an arithmetic number, because the mean of its divisors is an integer number (788158735).

Almost surely, 2^12156582321 is an apocalyptic number.

It is an amenable number.

12156582321 is a deficient number, since it is larger than the sum of its proper divisors (6759227319).

12156582321 is a wasteful number, since it uses less digits than its factorization.

12156582321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30625 (or 30622 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The spelling of 12156582321 in words is "twelve billion, one hundred fifty-six million, five hundred eighty-two thousand, three hundred twenty-one".