12540205361 has 4 divisors (see below), whose sum is σ = 12541308912. Its totient is φ = 12539101812.

The previous prime is 12540205351. The next prime is 12540205387. The reversal of 12540205361 is 16350204521.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16350204521 = 7 ⋅2335743503.

It is a cyclic number.

It is not a de Polignac number, because 12540205361 - 2⁶ = 12540205297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12540205351) 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, 534551 + ... + 557516.

It is an arithmetic number, because the mean of its divisors is an integer number (3135327228).

Almost surely, 2^12540205361 is an apocalyptic number.

It is an amenable number.

12540205361 is a deficient number, since it is larger than the sum of its proper divisors (1103551).

12540205361 is a wasteful number, since it uses less digits than its factorization.

12540205361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1103550.

The product of its (nonzero) digits is 7200, while the sum is 29.

Adding to 12540205361 its reverse (16350204521), we get a palindrome (28890409882).

The spelling of 12540205361 in words is "twelve billion, five hundred forty million, two hundred five thousand, three hundred sixty-one".