12006515521 has 36 divisors (see below), whose sum is σ = 16532917716. Its totient is φ = 8635999680.

The previous prime is 12006515501. The next prime is 12006515527. The reversal of 12006515521 is 12551560021.

It can be written as a sum of positive squares in 2 ways, for example, as 2368184896 + 9638330625 = 48664^2 + 98175^2 .

It is not a de Polignac number, because 12006515521 - 2⁷ = 12006515393 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12006515521.

It is not an unprimeable number, because it can be changed into a prime (12006515527) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 810 + ... + 154963.

Almost surely, 2^12006515521 is an apocalyptic number.

12006515521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12006515521 is a deficient number, since it is larger than the sum of its proper divisors (4526402195).

12006515521 is a wasteful number, since it uses less digits than its factorization.

12006515521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155822 (or 155804 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 28.

The spelling of 12006515521 in words is "twelve billion, six million, five hundred fifteen thousand, five hundred twenty-one".