12135575521 has 8 divisors (see below), whose sum is σ = 12340413288. Its totient is φ = 11930928000.

The previous prime is 12135575503. The next prime is 12135575533. The reversal of 12135575521 is 12557553121.

It can be written as a sum of positive squares in 4 ways, for example, as 129600 + 12135445921 = 360^2 + 110161^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 12135575521 - 2⁵ = 12135575489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12135575581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84141 + ... + 177061.

It is an arithmetic number, because the mean of its divisors is an integer number (1542551661).

Almost surely, 2^12135575521 is an apocalyptic number.

It is an amenable number.

12135575521 is a deficient number, since it is larger than the sum of its proper divisors (204837767).

12135575521 is an equidigital number, since it uses as much as digits as its factorization.

12135575521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95123.

The product of its digits is 52500, while the sum is 37.

The spelling of 12135575521 in words is "twelve billion, one hundred thirty-five million, five hundred seventy-five thousand, five hundred twenty-one".