12135561 has 8 divisors (see below), whose sum is σ = 16209600. Its totient is φ = 8075952.

The previous prime is 12135551. The next prime is 12135577. The reversal of 12135561 is 16553121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12135561 - 2¹⁹ = 11611273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12135521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1461 + ... + 5138.

It is an arithmetic number, because the mean of its divisors is an integer number (2026200).

Almost surely, 2^12135561 is an apocalyptic number.

It is an amenable number.

12135561 is a deficient number, since it is larger than the sum of its proper divisors (4074039).

12135561 is an equidigital number, since it uses as much as digits as its factorization.

12135561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7215.

The product of its digits is 900, while the sum is 24.

The square root of 12135561 is about 3483.6132104469. The cubic root of 12135561 is about 229.8017257849.

Adding to 12135561 its reverse (16553121), we get a palindrome (28688682).

The spelling of 12135561 in words is "twelve million, one hundred thirty-five thousand, five hundred sixty-one".