12405440135555 has 4 divisors (see below), whose sum is σ = 14886528162672. Its totient is φ = 9924352108440.

The previous prime is 12405440135551. The next prime is 12405440135581. The reversal of 12405440135555 is 55553104450421.

It is a happy number.

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

It is not a de Polignac number, because 12405440135555 - 2² = 12405440135551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12405440135551) 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, 1240544013551 + ... + 1240544013560.

It is an arithmetic number, because the mean of its divisors is an integer number (3721632040668).

Almost surely, 2^{12405440135555} is an apocalyptic number.

12405440135555 is a deficient number, since it is larger than the sum of its proper divisors (2481088027117).

12405440135555 is an equidigital number, since it uses as much as digits as its factorization.

12405440135555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2481088027116.

The product of its (nonzero) digits is 1200000, while the sum is 44.

Adding to 12405440135555 its reverse (55553104450421), we get a palindrome (67958544585976).

The spelling of 12405440135555 in words is "twelve trillion, four hundred five billion, four hundred forty million, one hundred thirty-five thousand, five hundred fifty-five".