12561333687 has 32 divisors (see below), whose sum is σ = 21276380160. Its totient is φ = 7175031840.

The previous prime is 12561333667. The next prime is 12561333749. The reversal of 12561333687 is 78633316521.

12561333687 is a `hidden beast` number, since 1 + 2 + 561 + 3 + 3 + 3 + 6 + 87 = 666.

It is not a de Polignac number, because 12561333687 - 2⁶ = 12561333623 is a prime.

It is a super-2 number, since 2×12561333687² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561333647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 515593 + ... + 539405.

It is an arithmetic number, because the mean of its divisors is an integer number (664886880).

Almost surely, 2^12561333687 is an apocalyptic number.

12561333687 is a deficient number, since it is larger than the sum of its proper divisors (8715046473).

12561333687 is a wasteful number, since it uses less digits than its factorization.

12561333687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26620 (or 26614 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The spelling of 12561333687 in words is "twelve billion, five hundred sixty-one million, three hundred thirty-three thousand, six hundred eighty-seven".