12540666613 has 4 divisors (see below), whose sum is σ = 12541583808. Its totient is φ = 12539749420.

The previous prime is 12540666527. The next prime is 12540666637. The reversal of 12540666613 is 31666604521.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12540666613 - 2²⁵ = 12507112181 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12540666113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 437773 + ... + 465538.

It is an arithmetic number, because the mean of its divisors is an integer number (3135395952).

Almost surely, 2^12540666613 is an apocalyptic number.

It is an amenable number.

12540666613 is a deficient number, since it is larger than the sum of its proper divisors (917195).

12540666613 is an equidigital number, since it uses as much as digits as its factorization.

12540666613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 917194.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 12540666613 in words is "twelve billion, five hundred forty million, six hundred sixty-six thousand, six hundred thirteen".