12115215505 has 4 divisors (see below), whose sum is σ = 14538258612. Its totient is φ = 9692172400.

The previous prime is 12115215481. The next prime is 12115215517. The reversal of 12115215505 is 50551251121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6262506496 + 5852709009 = 79136^2 + 76503^2 .

It is not a de Polignac number, because 12115215505 - 2⁵ = 12115215473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1211521546 + ... + 1211521555.

It is an arithmetic number, because the mean of its divisors is an integer number (3634564653).

Almost surely, 2^12115215505 is an apocalyptic number.

It is an amenable number.

12115215505 is a deficient number, since it is larger than the sum of its proper divisors (2423043107).

12115215505 is an equidigital number, since it uses as much as digits as its factorization.

12115215505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2423043106.

The product of its (nonzero) digits is 2500, while the sum is 28.

Adding to 12115215505 its reverse (50551251121), we get a palindrome (62666466626).

The spelling of 12115215505 in words is "twelve billion, one hundred fifteen million, two hundred fifteen thousand, five hundred five".