12136405521 has 4 divisors (see below), whose sum is σ = 16181874032. Its totient is φ = 8090937012.

The previous prime is 12136405517. The next prime is 12136405537. The reversal of 12136405521 is 12550463121.

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.

It is not a de Polignac number, because 12136405521 - 2² = 12136405517 is a prime.

It is a super-3 number, since 3×12136405521³ (a number of 31 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12136405571) 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, 2022734251 + ... + 2022734256.

It is an arithmetic number, because the mean of its divisors is an integer number (4045468508).

Almost surely, 2^12136405521 is an apocalyptic number.

It is an amenable number.

12136405521 is a deficient number, since it is larger than the sum of its proper divisors (4045468511).

12136405521 is an equidigital number, since it uses as much as digits as its factorization.

12136405521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4045468510.

The product of its (nonzero) digits is 7200, while the sum is 30.

Adding to 12136405521 its reverse (12550463121), we get a palindrome (24686868642).

The spelling of 12136405521 in words is "twelve billion, one hundred thirty-six million, four hundred five thousand, five hundred twenty-one".