12561305623 has 4 divisors (see below), whose sum is σ = 12767228728. Its totient is φ = 12355382520.

The previous prime is 12561305597. The next prime is 12561305677. The reversal of 12561305623 is 32650316521.

12561305623 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12561305623 - 2²¹ = 12559208471 is a prime.

It is a super-2 number, since 2×12561305623² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561305683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102961461 + ... + 102961582.

It is an arithmetic number, because the mean of its divisors is an integer number (3191807182).

Almost surely, 2^12561305623 is an apocalyptic number.

12561305623 is a deficient number, since it is larger than the sum of its proper divisors (205923105).

12561305623 is an equidigital number, since it uses as much as digits as its factorization.

12561305623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205923104.

The product of its (nonzero) digits is 32400, while the sum is 34.

The spelling of 12561305623 in words is "twelve billion, five hundred sixty-one million, three hundred five thousand, six hundred twenty-three".